Gearbox swapping and driveshafts

[Piet]

Hello all,
I am getting to the point where I will have to swap my gearbox. I have a late '67 4 speed car with a 334 gearbox which is losing all its synchros and a new 354 gearbox I bought from Renault some years ago in anticipation.

So, you say? So far, so peachy, stop boasting...

The question I have is relating to the driveshafts- I also sourced a pair of later R4/R5 driveshafts to go with the new box. The car has the pre 1969 7 degree castor front suspension which has a slightly narrower track than the later cars. With the old style driveshafts (attached with the roll pins) you had to make sure you had the right length or the suspension could jam up.

Is this a potential problem with the new ones, or do they have enough axial travel to obviate this? Do I need to get them shortened?

Has anyone fitted a 354 and driveshafts to an early pre 69 car and did they have any trouble????

Any answers would be a great help.

Cheers

 

[benchseat]

Can't help with the question : but I had a type 334 many years ago. Synchromesh between 1st and 2nd was non-existent and between 2nd and 3rd was not so good. But as long as you remembered to double-declutch (raise clutch when gear lever is in neutral position before depressing clutch again and engaging new gear) it was perfectly OK and did me well for several years. So is a gearbox swap necessary if it may lead to other problems?

Another point : there are still many R4s on the European mainland and there seem to be quite a lot of old ones in scrapyards. Possibly a 334 box could be sourced from there if a French forum member was willing to help. I believe that any 334 will replace any other one (the only difference is that some have the starting-handle dog blanked off).

 

[Piet]

Thanks for the thoughts but... I think any other 334 will be just as stuffed. Plus if I put an unknown box in I'd be replacing seals and bearings as a precaution, to ultimately get something just as bad if not worse! Also, I have been double declutching for years now, and even doing that you have to be slow and careful. The worst is actually some of the up changes. The thing that is really driving it is wife and now driving age children baulk at the shift pattern as well as the declutching.

I certainly won't be throwing it away though, one day I would like to rebuild it with new synchros- I suspect they can be found in france if you know the right people, just as all sorts of 4CV parts now see the light of day (for the right person and the right price). But thats a project for old age, and will have to wait in a queue of three speed bicycles, O gauge trains and various other pieces of mechanical detritus!

 

[angel]

I'm afraid you can't do this, the 354 driveshafts are already a rather tight fit in the late front end, and there may not be any space in the inner joints to compress more.
You may try a dry build with torsion bar removed and all bushes loosened in order to check if the driveshafts reach the end of their travel or not, before having them shortened.

 

[Piet]

Hi Angel, thanks for weighing in ..... Rats! I was hoping that wasn't the case.
When you say they are a tight fit, you don't know roughly how much can the inner end be pulled outwards from its detent before it gets solid? I don't want to pull a torsion bar out, but I might do a kinematic layout to see how much the length varies over suspension travel.

Looking at the specs the difference in track per side from '68 to '69 looks like it is of the order of 17-20 mm. So perhaps it is safest just to get the shafts shortened by that amount and balanced. I could put both assemblies together on the workshop floor and just measure their overall width before deciding.

On the other hand, the new driveshafts Renault supplied in latter years for roll pin type driveshafts (as opposed to the plethora of different types they provided during manufacture) seem to fit OK on all models- My current 328 gearbox has a pair of those, and they are the same part number supplied for all early 4 speed and late 3 speed cars, and they have never bottomed out. Those shafts have the same joints as the later ones (only the inner attachment to the box is different), so if Renault had their act together they could have designed the new gearbox and shaft combination to fit both early and late suspension cars....if they had bothered of course.

 

[benchseat]

I'd still consider the French option. Last time I was there I saw several 334 types going strong. And I have one myself, admittedly with very low mileage. There are quite a few Forum members in France (English speakers) who might be willing to attack the scrapyards. Delivery would be expensive, of course. PS. O Gauge trains . . . . now that's more like it!