INFO: Gearbox / Linkage

 Talbot Express / Peugeot J5/ Citroen C25 (and comparable FIAT Ducato models)

 Gearbox & Linkage 

Introduction:

The Talbot Express base vehicle is one of the “Sevel” type manufactured by the PSA group in Italy. Known as the Peugeot J5  and marketed under the Talbot brand in the UK (Peugeot owned the brand at that point). It shares almost all of the mechanical elements with the Citroen C25 and Fiat Ducato, although it should be noted that Fiat parts differ in many cases, most noticeably with their Diesel engines which are of a later type.

Mechanically the vehicles are regarded as having a very robust engine (in petrol form at least), although they are all getting very old now and may be showing age-related issues or appearing on the market with the cumulative effects of poor maintenance.

They have a reputation for gearbox problems predominately in the Right hand drive format. I have spoken with people who used to run Fleets of Talbot Expresses and these people confirm that the linkage was quite imprecise even when new.  Worrying too is the number suffering from worn out synchronmech on 2nd / 3rd gear even after relatively low milages, e.g. 60k + 

Literally hundreds of vans have been presented to me for repair/upgrade of the Gear linkage over the years and these pages are my observations.

Whilst imprecise Gear selection issues can effect vehicles slightly different ways almost all are attributable to:

• Idler relay assembly,
• linkage arm ball sockets,
• loose balls
• worn base of gear lever to main control arm joint

1) Worn synchromesh (crunching into gear NOT attributable to incorrectly adjusted clutch). Most noticable changing down from 4th to 3rd or 3rd to 2nd
2) Failure to stay in 5th gear (internal gear fault / engine mountings and/or indent spring)
 

GEAR LINKAGE

Before getting into the detail it is worth mentioning here that no amount of fiddling with the existing gear linkage is going to correct

• a worn linkage,
• soft engine mounts, 
• incorrectly adjusted clutch cable, or worn clutch.
• worn out synchromech

Similarly no amount of quality Oils and/or additives is going to alleviate imprecise selection issues caused by worn gear linkage mechanism and/or selector shaft bush. 

How to change gear:
When performing gear changes on these vehicles be gentle but firm. This is a old vehicle design from the early 1980s and the gear change should not be rushed. It will never  be as “silky smooth” as your average car. 

Gear Linkage Overview 
There are  4 types of gear linkage fitted to these vehicles.

 Left Hand Drive

The Talbot Express etc were originally designed to be Left hand drive using a column change up to 1991 and a dash-board mounted mechanism from 1991 onwards.

 Left Hand Drive up to 1991 

On the Left Hand drive models the linkage was attached directly into the top of the gearbox. and acts in-line with it. The column change method has considerably fewer joints so is less prone to freeplay in the linkage, and does not exert excessive lateral pressure on the selector shaft collar. It is for this arrangement that the gearbox selector shaft collar (not shown) was designed and although wear  here can be an issue worth addressing with an oversized O-ring or Sleeved collar (see later) this is usually the only thing that needs addressing.

LEFT HAND DRIVE
Column Change up to 1991

 Left Hand Drive 1991 Onwards  

The left-hand drive cable operated system from 1991 onwards is quite complex with many joints/bearings all of which can be a problem.

I can supply/fit the input shaft collar for these but further bearing bush replacement will have to be custom-made with the vehicle/parts here.

LEFT HAND DRIVE
Dash-Mounted Gear Change Components
  1991 Onwards

 Right Hand Drive

To accommodate a floor change for Right hand drive vehicles a rather complex mechanism of levers and joints was implemented.

It is a combination of this mechanism and the lateral force it imposes on the selector shaft that is responsible for the wear which results in a “sloppy” imprecise gear selection (even banging your hands on the dashboard in extreme cases). 

 RHD Pre-87 models: 

Note that the earlier (pre-87)  gear linkages used can be identified by having two rods attached to the base of the Gear lever.

The earlier version is prone to a number of faults:

1. Bending/snapping of the long-thin selector rod,
2. Wear / snapping of the linkage where it is bolted to the bottom of the gear lever itself.
3. Snapping of the welded stud for the crosslink

The picture opposite shows a poorly repaired lower bracket that was presented to me for repair in 2011 where the weld was failing.  Unfortunately I was unable to save it and the owner has subsequently updated to the later linkage style.

If you have a broken lower bracket where it connects to the base of the gear lever then it is almost certainly worthwhile replacing the whole assembly with the later later version from a breakers. Alternatively the base of the gear lever can be welded but this will require a powerful welder and is unlikely to last very long.

RIGHT HAND DRIVE
Earlier Style Gear linkage (Pre 87)
Long Rod is 350mm , short is 155mm (between ball centres)

Right Hand Drive 1987 Onwards:

The image  shows the later (and much more common) 1987 onwards gear linkage layout.

This information on this web page predominately relates to this 87 onward linkage shown on the right, however many of the same issues apply to the earlier version, especially the selector shaft collar/O-Ring housing, relay and linkage arms.

As you can see from the pictures there are lots of components to the linkage assembly. Wear can occur in any or all of them so check each one with the aid of an assistant prior to replacing them.

There are several places for free play to develop so do not be too hasty to diagnose a specific joint, although predominately the Sleeved Input shaft collar, Relay upgrade and base of gear lever are all badly in need of refurbishment. 

RIGHT HAND DRIVE
Later Style Gear linkage layout (87 onwards)

Long Rod is 159mm , short is 111 (between ball centres, +/- 1.5mm)
 

Revised gear lever length ( 90 -Onwards models):
Note the different length of gear lever shown here. Both are are the later post-87 model, the shorter one without the floor spacer is a early version (87-90 approx) of the revised linkage, and the longer version with the floor spacer was introduced later (approx 1990) to reduce gear lever travel. The later versions also did away with the neutral spring on the Idler relay, and had a strengthened drop arm on the main control arm linking to the base of the gear lever.

Base of gear lever modification. ( 87 onwards models)

A time-consuming process necessary to address excessive freeplay where the hole at the base of the gear lever has become elongated (worn) and the bushes are worn in the main control arm.

Details of this modification have been removed due to others copying my work and doing badly, suffice to say that the modification is time-consuming but VERY worthwhile if you have free play in this area

Drop-Arm Fracture ( 87-Onwards models)

Early versions of the 87-onwards linkage also suffered from a weakness in the drop-arm which was strengthened in later versions.

Wear points: 
(Originally written in 2006 this section has been updated in 2009 and 2013 as several items are now  no longer from the main dealers (denoted by NFP below). 

• Selector Shaft Collar / Bush:  This collar/bush is one of the prime locations for excessive wear. Originally designed for a LHD column change where the turning motion acted along the axis of the shaft it is insufficiently bushed to withstand the forces exerted upon it. It wears significantly over time. The inner metal bush surface wears away and then the whole item wears into an oval shape. Corresponding  wear grooves are ground into the side of the input shaft itself in 3 distinct heights that match the gate positions (up, middle and down).  There are 2 options for addressing this wear:

• Idler Relay / Control Return Assembly: The relay is the horizontal pivoting device that runs across the top of the box. It has an 8mm bolt running horizontally through it with a steel spacer and nylon bushes. The relay wears in several places including enlargement of the holes in the mounting bracket over time. It requires substantial modification to address this correctly for the longer term. I offer a modified relay incorporating a larger through bolt and full-length metal bushes. The modified relay has  virtually zero free play and should last for the lifetime of the vehicle. It is provided with a grease nipple to ensure a long service life and whilst re-greasing is NOT essential I advise it be done at the 12 monthly service intervals. This is Relay unit is an exchange item.
   

• Base of Gear lever(1): For Pre 87 models is almost impossible to fix if fractured and I strongly recommend you upgrade to the 87-onwards gear lever arrangement. Provided the bracket is not fracturing then I should be able to reduce some/all of the free play where the bracket bolts to the base of the gear lever but I don't guarantee it on these early models as the whole design is flawed. 
   

• Base of Gear lever(2): On later versions (87 manufacture year onwards) the hole through which the bolt passes often becomes elongated together with wear in the control arm metal bushes, and the through bolt, and even the holes in the main control arm). I can address this but ONLY with the van here as it is very difficult to assemble/fit correctly on the vehicle and needs to be carefully adjusted in-situ.
  
  Free play at the base of the gear lever on 87-onwards models is increasingly becoming a major issue and can contribute significantly to and overall worn linkage. It is now an integral part of the linkage upgrade service I offer here.

• “Ball” sockets: The ball sockets used to be available with the selector rods for either £63 or £50 from Peugeot depending on which rod you require, however they are no longer available. I provide new arms using plated balls with stainless linkages for a fraction of this price. If these are loose or seizing (stiff) they should be replaced. If the balls themselves are worn/damaged these can be replaced but the effort and cost of doing so depends on which one(s) need doing so contact me if this is the case. The idler relay and control sleeve balls are straight forward but  replacing balls on the later drop arms can be very  problematic and is seldom done as the cost would outweigh the marginal improvement.
  
  The linkage arm that wears the most is usually the one that connects to the rear of the idler relay assembly but if the work is being done here then all 3 are usually replaced as it makes for a superior job.  
    

• Broken Control Sleeve: This is the assembly right at the front which bolts only the top of the selector shaft where it enters the top of the gearbox. These sleeves either rust and then snap (early models, can often be re-welded) or are crushed and broken by incorrect fitting (later models). They are irreplaceable new so take care. In the case of the later version that uses a round Allen-head bold the bolt must be fitted so the round head fits inside the larger round hole in the control sleeve (fitted from the REAR). Fitting it the other way around will crush the collar and weaken it considerably leading to the collar snapping. I have seen a lot like this over the years. 
   

 (also see the section on Engine mounts below).  

Modified Relay Shaft

• Metal  bushes that run the entire length and a tight fit exactly into each Relay shaft.
• It is machined to fit snugly onto a new and much larger through-bolt with a longer shoulder than the original, and to a much finer tolerance.
• The mounting bracket is also modified to remove the oval wear in the bolt holes and to accommodate the larger though bolt. 
• A grease nipple is drilled and tapped into the main body fitted to provide additional periodic lubrication.

The issue with the relay is almost always free play between the spacer and the through bolt plus the through-bolt wearing the mounting bracket holes oval,  therefore both parts have to be modified and removing them in this manner is a very effective method.

Modified free-play linkage assembly with virtually ZERO free-play available from the author in the ForSale Section

Selector (Neutral) Spring?

The Neutral Selector spring fits on the relay as shown. It is powerful spring that supplements those in the gearbox responsible for positioning the gear lever between 3rd and 4th when in Neutral (just like a car).

ALL vans have Neutral springs inside their gearbox but NOT all vans have a spring fitted to the relay as well.  They were dropped in the later (approx 1991 manufacture) when the gear lever was extended below the floor.  You should NOT fit a spring if you do not already have one fitted as doing so makes the side-side movement of the gear lever excessively heavy and tiresome on the later models.

THE FULL WORKS
(althoug not showing the base of gear lever mods)
 (image for information only as the front piece (the "Control Sleeve") to which the linkage arms attach is the original item cleaned and painted, I do not usually sell that part.)

It comprises

• Modified  Relay / control return
• Sleeved input shaft collar
• 3 x New Stainless steel and electro-plated Linkages

(in this case the control sleeve at the front has also been painted but this is not usually the case as the customer's original control sleeve is refitted (with new balls if necessary)

Engine Mounts:

It should be noted that there are other factors that can contribute to this imprecise gear selection, most notably the engine mounts which go soft quite quickly allowing the engine/gearbox to move around a considerable amount effectively altering the linkage geometry. 

If the linkage is worn this movement can render some gears un-selectable one moment then fine again the next. This is particularly true of the side mountings and unfortunately these are very hard to check in-situ other than the imprecise method of observing the amount of movement in the engine/gearbox unit.

It should be noted that a good (uprated) linkage can usually handle worn engine mountings, though personally I'd prefer owners to change the mountings too as it "firms up" the engine/garbox unit and makes for a more precise feel

Clutch:

The above assumes your clutch is not dragging, which will result in gears "crunching" when selected with the vehicle stationary and the engine running. For correct clutch adjustment the pedal should be the same height or more typically up to 2cm higher then the brake pedal. The extra cm is to allow for the thicker carpets fitted to motorhomes. The clutch is adjusted using a nut on the end of the cable where it attaches to the control arm on the bottom of the gearbox bell housing. If your Motor home has thick carpets increase the pedal height to allow for this. Be aware that it is usually necessary to depress the clutch pedal fully to the floor before selecting gears.

Oils and Other issues:

Other issues with the box relate to using the correct oil, oil level modifications and potential (although unlikely) problems with water ingress .

 Jumping out of Gear:

1) Under acceleration / deceleration the engine/gearbox unit is moving excessively on its mountings and pushing the linkage out of gear. Possible temporary Fix - Experiment with adjusting the fore-aft linkage rod length one turn at a time. If this works then permanent fix is to change the engine/gearbox mountings focusing on the LH and Rear Mounts.  

2) Internal gearbox problem

(a) Most likely the gears themselves can be worn. This is not something I can assess and you'll need an internal gearbox specialist.
b) when you put a load on the gears it throws itself out of gear due to worn detent spring. This is a spring with a small ball bearing and as you change gear the cogs slide over this small ball and it locates in a detent to hold the gear in place. If the spring fails then there is no resistance to hold the gear hence it is forced out of  gear as under load (acceleration or deceleration).
3) There may be other causes for it jumping out of gear. There is one person I know of who’s linkage perished where the gear lever goes through the floor and the lever “bouncing around” was sufficient to pull it out of gear in some cases


OIL:

GL5 or GL4 Spec? :
There has been debate over many years whether to use GL4 or GL5 spec oils as both are mentioned in different official sources (e.g. Owners's manuals for the base vehicle).  Typically GL4 was mentioned in the earlier user handbooks and GL5 in the later ones.  It appears that the GL5 entry may simply be a "typo"

Officially GL5 is listed as:
1) backwards compatible with GL4
2) recommended for combined Gearbox/differential units as fitted for these vans
3) supposedly better for the bearings.

However (and here is the real crunch) GL4 spec is potentially better as the GL5 specification is reputed to attack the soft metal of the synchromech. We need a verifiable peer-reviewed source rather than a single internet article that appears to be fuelling this debate.
 
I used to offer GL5 based on the vehicle manufacturer's user handbooks (the later ones), however several years ago I switched to only offering customers  80w/90 GL4 spec to be on the safe side, unless they specifically ask for an alternative. You may also bring your own oil if you prefer (1.9L required for 2 wheel drive, 2.5L for 4WD).

 
OIL CAPACITY / LEVEL:

Intro:
The gearbox and differential share the same oil. For those that don’t know, the dipstick is accessible at the rear of the G/box by
(a) reaching through the NS wheel arch, or
(b) Removing the spare wheel and getting to if from under the bonnet, or
(c) raise the vehicle all round and get at it from underneath (my preferred method).
 
CAPACITY: (and dipstick markings)

Simply: ** Drain and fill to 1.9L (One point NINE ) even though the manuals state 1.6L **
(Unless a 4x4 in which case 2.5L)

If you do overfill the box all that happens is excessive seepage occurs through the gearbox breather (on top of the box) typically at speeds of 55/60+. The seapage stops when the excess oil has been pushed out, although it does make a mess.

Note that oil is NOT  forced passed the drive shaft seals or speedometer cable entry point unless these seals are already faulty.  

EARLY DIPSTICK
(Do not use these markings which represent 1.25L. The later markings should be 20mm higher at 35 and 40mm )

INCORRECT OIL LEVEL DIPSTICK INFORMATION WARNING:
Sometime in early 2005  one of the motorhome magazines ran an article stating that the oil level should  be increased to approximately 20mm down from the top of the dipstick and the dipstick re-marked manually. This is nonescence and there no "official" reference to such a change. I believe them to have been mis-informed/confused by the manufacture raising the existing oil level markings by 20mm as mentioned above and NOT that they should be 20mm down from the top as reported. 

OIL FILLING AND BREATHING:

It is advisable to fill with oil via the Reversing light switch. The official manual goes further and states that you MUST fill through the reversing light switch and NOT through the dipstick hole.  

The reason is that the Gearbox and Differential casings are separated by a high barrier (oil baffle/weir ) so one side fills before the other. This baffle is to prevent  the oil shifting away from the Gears under acceleration. 

The dipstick goes in via the back of the differential casing, so IF you fill through this (rear) hole and the vehicle was not level it might (conceivably) be possible to fill the differential casing without getting sufficient oil in the gearbox. 

I always fill through  either the reversing light switch or breather hole (both of which go straight into the gearbox)  as instructed to be safe.  

Whilst you are working on the top of the box take the opportunity to carefully clean the area around the breather (just ot the left of the relay when viewing from the front of the engine bay) then pull it out (it comes straight up) and clean the breather itself.  The location of this breather is potentially a problem  with water ingress through the original breather plug a slim possibility, as the rain water discharge pipe from the heater air intake is positioned directly over it. Make sure your breather plug is not missing, and if you are worried about water already in the Gearbox/final drive then change the oil (2 drain plugs, and see capacities noted above))

If you’re thinking “why don’t I just block the breather” then don’t as it is there to release the pressure inside the gearbox/final drive caused by the oil expanding as the temperature rises. If you block the breather the gearbox internal pressure will increase and you risk blowing oil past the drive shaft seals. This is not only messy but could eventually lead to a seriously low oil level going unnoticed. It might also warrant replacement of the Driveshaft oil seals and this is something to avoid if possible as removal of the inner drive shafts where they enter the differential can lead to serious damage of the shaft and gearbox casing if not done with care. Basically don’t block the breather! 

** DO NOT PRESSURE WASH THE GEARBOX **
I have seen some boxes here that have an incredible amount fo water in their oil and it can only have occurred by being forced in through the breather.

ENGINE MOUNTINGS:

Unfortunately these can have quite and impact on gear selection in some cases. More importantly the Rear Engine mount can also be a contributory factor in snapped exhaust manifold studs in the cylinder head on petrol-engined model which requires tricky and/or expensive repairs. 

Rear Mounting:

Worn Rear Mount allowing the engine / gearbox to rock front-rear when driving

Engine pitching manifests itself as excessive fore-aft movement at the gear stick, possible fingers hitting the dashboard.

Side Mounts:

Can make finding gears on corners/inclines difficult, and can contribute to clutch judder. If you cannot reach 2^nd whilst pulling away on a left hand corner or you cannot engage reverse when the van is leaning to the left then this is probably the cause.

The amount of left-right movement in the stick is limited by the control bearing bracket under the passenger floor so excessive side mounting movement can result in insufficient gearlever travel to reach either the 1/2 or 5/R gates under certain circumstances.  Do NOT open up the control bearing bracket as this will over-stress the selector forks inside the gearbox (leading to a much more serious and costly repair). 

The rear mountings wear out very quickly. From approx 1991  the vans were fitted with a larger (85mm) rear mounting but even these larger mountings can be badly worn after relatively low mileages (e.g. <35k miles in my case).  If you have a  70mm mounting these wear out even faster, ridiculously quickly on the higher-torque engines or if your side mountings are also worn as these allow excessive “yaw” movement in the engine/gearbox assembly.  Almost every van presented here for work has a badly worn rear mounting.

Note that you cannot fit the larger rear mount to the 70mm bracket without also replacing the bracket that connects to the floor of the van.

The 2 engine side mounts if badly worn allow the engine/gearbox to "bounce around' on corners/rough ground contributing to imprecise selection, and if parked on a left-hand slope you may find you cannot reach the reverse gear as the whole unit has shifted to the left meaning there is insufficient gear lever travel to reach it (note in an emergency you can select reverse manually by opening the bonnet, locate the control sleeve on top of the gearbox, and with the van in neutral firmly press it Down then Clockwise to select reverse) . 

PRE-LOADING THE LH ENGINE MOUNT (TEMPORARY repair when missing Reverse)

This issue usually manifests itself as being unable to select reverse gear under certain conditions. This is because under certain conditions such as leaning  left the weight of the engine pushes the gearbox to the left and effectively messes with the adjustment of the gear linkage. If the engine mounting has been preloaded it resists this movement and helps preserve the linkage adjustment.

To adjust:

loosen the 4 bolts then:

• lever the gearbox back and to the left (when viewed from the front). 
• move the mounting plate (the thing on top that the 4 bolts go through) to the front and NS relative to the gearbox.

Hold it there and tighten the bolts to the correct torque (50 Nm  /  37 Ibf ft).