UN1 4 spider diff settings

Kevin Box

Supporter
Gents

I am in the process of setting up the 4 spider diff in my UN1.
Initially the shims behind the planetary gears (spiders) were very worn and I was having difficulty finding some new or second hand ones.
After visiting the local company Adelaide Differential Services, he managed to find some shims for me. They are from Borg Warner diffs as fitted to Aussie Fords and Holdens.
My question is - How tight should I set the backlash in the 4 Spider now that I have a selection of shims to play with ?????
My gut feel is to get it as firm as is practical and hopefully with as closer backlash as posible on all 4 spiders.
I'd appreciate any comments here.

Thanks in anticipation

regards Kevin B

:idea::thumbsup:
 
Last edited:
I cant comment Kevin, but this diff you are using - what is the box number, as only the V6 Renaults, 369 R30s and Alpines has the 4-spider diff. (did I miss one?)
Just a matter of interest, where did you get your box from?
 

Kevin Box

Supporter
Bruce

The transaxle is a UN1-13 and the four spider diff centre is one I got from Eurospeed Motorsport - it is most likely from one of the tranaxles you mention.
I have machined the carrier to be the same as the UN1-13 carrier so it will support the speedometer drive.

I now have a good selection of shims but have little or no information on the correct setup of the side gears and spiders.
In one sense I thought I should shim it up quite tight but the other side of me says try to achieve factory setting and possibly go one step further and do the best I can to make sure the for spiders load equally to share the torque evenly.

I would appreciate any help you can give.

I will put some pictures up later in the week if time allows.

Cheers Kevin B

:thumbsup:
 

Kevin Box

Supporter
Bruce

UN1-13 came off Trademe in NZ

Also curious if anyone has set up a concentric hydraulic release bearing on UN1 as there is not much room in the bellhousing
I am using an aftermarket clutch but basically Ford SBF dimensions.

Cheers
KB
 
Last edited:
hi Kevin, I dug this up from my collection, it does cover the settings for a UN1 diff hope it helps.
Graeme
 

Attachments

  • renault gearbox service manual.pdf
    904.8 KB · Views: 304

Kevin Box

Supporter
John

With the lack of information around on setting up the spiders, I basically set myself 2 objectives

1 Try to get the 4 spiders all taking the load
2 Minmise the backlash as much as was practical.

The original Renault shims are supposed to be appoximately 1.0mm thick.
The ones I had out of my 2 spider were around 0.55mm & 0.6mm respectively. The ones that cames withe the 4 spider were also quite worn ranging from 0.4 to 0.6 so no easy answer here.
After a lot of fruitless searching for genuine Renault parts and being offered some second hand ones for $100 a set, I figured there had to be a better way.
I visited a local diff shop and asked if he had any shims similar to the Renault ones. It turned out the BorgWarner ones used in Australian Holdens and Fords were almost identical except they are mad of steel shim and not brass.
They are fairly soft so should be no problem.
He gave me a whole handful some new and some not so new.
The next step was to to assemble one half of the diff in the vice and check the backlash was fairly similar on all 4 spiders. After a bit of swapping of shims I eventually ended up with similar back lash on all four - I didn't measure it, but from the feel it was resonably tight but probably had about .005" (0.125mm) backlash. It feels firm but not rock solid.
I then assembled the the crownwheel side of the diff and checked the other side gear was similar. I ended up having to put a shim behind the side gear in this side to get it the same. I was lucky that I had a spare one from the 4 spider to play with. I needed to make it thinner so 400 grit wet & dry on a surfacing plate and an hour or so later I had it done.
I could have made it tighter but could not see the need.
It definitely did helped having a large handful of shims to swap around to get the best solution.

I am not sure what the 4 spider came out of (possiblly UN5 ???) but I had to machine it to accept the speedometer drive that my UN1-13 has. Not a difficult thing but not easy if you dont have a lathe.

I guess the proof of my labour will be when I finally get my GT40 on the road.

regards

KevinB
 
Back
Top