G/box: 2WD: HOW TO: Tighten gearbox shafts nut/bolt on Renault gearboxes

[kilou]

Hi,

please read the following if you have following symptoms with your Renault gearbox (mounted on Volvo S/V40 phase 1 with atmospheric and diesel engines (M3P, M5P, M5D gearboxes only):

- 5th gear noisy or "coin-like" noise in any gear
- 5th gear jump out of gear (or other gears too)
- problem selecting some gears (not cured by renewing gearlinkage bushes)
- before trashing the gearbox or if the dealer told you the gearbox is dead!

All these symptoms can be caused by primary shaft nut or secondary shaft bolt coming loose and eventually falling off in the 5th gear carter. If you experience this please act ASAP as if the nut/bolt fall off in the carter they can potentially destroy your gearbox (many Renault gearboxes have failed this way!).

This procedure quickly explains how to tighten the primary shaft nut and secondary shaft bolt in Renault gearboxes This can be achieved with GB in place. Here on a M5P (JC5-222) gearbox from a 1997 Volvo S40 2.0 petrol:

1) Remove airbox assembly + drain gearbox oil
2) Support front of car on axle stands
3) Remove front left wheel
4) Support the weight of gearbox on a jack + piece of wood
5) Remove the gearbox mount (left engine mount)
6) Lower the jack until the 5th gear carter of the gearbox can be totally seen in the wheel arch
7) Unbolt the 5th gear carter and remove it (recover the gasket). This is what you see:


8) You need to lock the GB in 2 gears to unbolt the nut/bolt. Put the GB in reverse at the selector first. Then remember the position of the 5th gear fork before pushing it in to select the 5th gear.


9) Now unbolt the large retaining nut on the primary shaft and the bolt on the secondary shaft. Clean and degrease the threads thoroughly.

10) Remount these using strong LOCTITE frenbloc. It is advisable to use a new retaining nut on the primary shaft (I didn't...). The nut must be tightened at 135Nm and the bolt at 70Nm. Allow a sufficient time for the Loctite to dry (let it sit overnight).


11) Unlock the GB by pulling out the 5th gear fork manually. Take care not to pull too far though, just bring the fork back where it was before you pushed it in.

12) Remount everything back and refill the box with gearbox oil 75W80 API GL4+ /GL5 until it flows out of the filling hole. I used Kroon-Oil SP1051 which is a full synthetic oil + 2x20g Liqui Moly MoS2 gearbox additive that works better than the Volvo stuff for me.

13) Check operation. If the gearbox works as expected, you just acted on time. Congratulations!

[kilou]

A few remarks:

- Use LOCTITE n°270
- Do not pull the 5th gear fork too far when unlocking the gearbox
- Refill the gearbox with appropriate oil. Correct level is achieved when the oil flow out of the filling hole but make sure the car is level when doing this!

[Baffler]

Great write up Kilou This should save a few boxes from the scrap heap.

Would be great if you could increase the size of the pics

[kilou]

Originally Posted by Baffler

Great write up Kilou This should save a few boxes from the scrap heap.

Would be great if you could increase the size of the pics

Yes I hope it can be useful to some people. I don't know how to edit the post now to put larger pics, seems the delay is over...

[Rossobianchi]

Do you think this is possible/solution to having the 5th gear stuck in place? 9it wont come out.

I did have the sympons of - 5th gear noisy or "coin-like" noise in any gear
- 5th gear jump out of gear (or other gears too)