Transaxale tools and rebuild

[Gary Whitaker]

I had time today to do a little experiment I wanted to see what interference fit the bearings are
please note that this is just my experience of breaking down and rebuild of the transaxale , I in no way saying this is how you should do it yourself or implying that I am an expert, I am not, but skills are getting lost and the manual sometimes not the easiest to follow
If I can show some photos as I go then it will probably help someone else.

Back to the experiment the manual say you should heat the box to 100 degree before removing the bearings so is it really necessary ?
I measured a new bearing outside diameter and set my bore clock to zero
First photo shows it at room temperature 20 degrees

The bore clock is in mm .01 division so just under .05 mm .002"
On 54 mm which is the bearing size I think you would damage it cold

Now at 100degs size is over .04mm .0016"

So my conclusion is they should go in easily at 100 drgs but you will have to be quick the heat transfer will soon make them grow
Best regards Gary

[John A. Ross]

Thanks for sharing these snippets Gary. I always wondered how much of the "get up to X temperature" was just playing safe or not.

Heating / cooling cast parts always worries me a bit. Some folks reckon you can get things like valve guides in and out in one heat session but I reckon you would need to do it for a living for that.

- John

[Gary Whitaker]

You would have to do 2 heat up sessions as there's always oil left in there plus you need to calculate the shims required and that's done with the bearing out
best regards Gary

[moose549]

Good Progress there Gary. Will post some pictures later of the boxes i am doing at the moment. At a later date i will put up some pics of the running in rig i am building.

[John A. Ross]

The running in rig would be really nice Mike as basically everyone else just expects the box to be fitted to the car and try it.

I have already used the usual suspects for rebuilds rather than do it myself, relying on the experience more than the science but this has not had as good a track record on success as one would expect.

[Gary Whitaker]

Hi still waiting for the other tools to come , I should have just bought my own lathe.
measured for the pinion bearing head shims today
The tool required is RG 365
Brought the cleaned castings inside today let them come up to room temp for a couple of hours first


First photo is RG 365 dummy pinion head


Next is how you take a feeler gauge reading but is only to better show how it's done as you need to bolt on the clutch housing casting and tighten the 4 bolts




next to where the bearings fit

I also turned the box on its side so I could rotate the dummy pinion to get a better feel ,
It came out at .009"

I'll show the calculation later on when I check the pinion head shaft length ,they can vary slightly
Best regards Gary

[Gary Whitaker]

Taking reading all clamped down

[John A. Ross]

Nice work Gary, the picture a lot clearer than the manual.

John

[Carsten]

Hello guys,

I am new to this place, maybe some of you have read about me / my Mk1 Centaur on facebook or in the Imp club forum ?

Currently I am rebuilding my gearbox, and I need to borrow some tools if possible ?

I have to set the crown nuts / differential cage and gear play, I think it is RG 373 ? Then I also need
the tool to set the twin- slotted nuts on the rear end of the two main shafts.

In both cases I could make something from steel and old cheap toolsets, but if the proper tools are available
on a loan base I think this might be better.

Carsten

[John A. Ross]

Carsten, Gary was planning on making some for himself but bought a couple as well.

The club used to do this I think, but not any more, in fact the query on where the tools the club used to keep were caused a bit of a debate as no one seems to remeber.

Probably as it is such a job to do and the tools are rare, expensive, fair bit of experience needed and of course parts for most people it is cheaper to get one refurbished with Dave or Malcolm.

I reckon anyone setting up to do trasnaxle rebuilds these days (parts permitting) could keep a nice "imp" fund going.

It has been great to see the work on the Cntaur you post on facebook.

Not sure you will find any on a loan basis any more I am afraid Carsten but Garys rebuild is first "real" rebuild views I have seen outside the user manual that make things a little more clear.

- John

[Carsten]

Hi John,

thanks for your post - if I don‘t find any, I‘ll make something. Never give up, never surrender....

Carsten

[John A. Ross]

Carsten

I think thats an unofficial Imp moto !

[Gary Whitaker]

Hi just seen post and have commented on carstens Facebook post I will post everything that Carsten needs to post and can message him but I've been let down on the other tools I need so I can't do that just yet

[Carsten]

Hi Gary,

not sure if I understood your post fully - I already asked Malcolm for spares (he has a lot to do he said so I‘ll keep waiting). If I can get help from you that would be very nice !

I need:

- selector rod for late box, mine is bent. I can try to use an early one but at least one difference is that the early selector shadts have a cutout for the O- Ring, whilst the later ones have the O- ring embedded in the case, so I‘d have to weld / grind / polish it, which does not really make sense after all.

- rear upper input shaft bearing, it is a roller bearing type (I guess earlier boxes had the 6204 cylindrical standard bearing fitted and later ones were fitted with a roller bearing ?), it seems to be the same as the lay shaft bearing.

- a set of seals, 2x output 1x input shaft behind clutch, because I want to repair my spare Rootes-3 box as well when I am at it. I will not invest any work into the early Rootes-1 which I also have, makes no sense as it oiled a lot anyway.

Tools:

1x to fasten the input shaft nuts, I guess it is a tabbed socket with two „tongues“ ? which slide over the nuts ? I could make my own from an old socket - take one that just fits, cut two slots, weld in 2 old nuts to block the slots in the gearbox nuts, job done.

1x crown tool to set backlash / re- fit the crown nuts in the Rootes-3, and check in the Rootes-5.

Many thanks !

Carsten

[Gary Whitaker]

Hi the socket for the nuts cane made I've slotted a socket and welded a bit of key steel in or a suitable ballbearing can be used but I don't like that idea as it may fall in the box ,the cage nut tool to set the preload and alter the backlash , you need 2tools 1for each side as you set the preload first then move both cage nuts together to alter the backlash while keeping the preload set.
I just made a rectangular bar cut to fit in the slots and a bar welded to it
Malc can sort parts out but if you want any know how just let me know as I can post photos on here .
Do you know which selector is bent as the are different or is it the rod that sticks out of the box ?