Transaxale tools and rebuild

[Gary Whitaker]

[Gary Whitaker]

[John A. Ross]

New lathe working out well then Gary

[Gary Whitaker]

The pinion shaft gears all run on oilite bushes and when I stripped them down there did look like wear on the bushes to cut a long story short theses are a non STD size and I had no Idea of what running clearance should be so I bought a new set from Malcolm .but how long stock will last I don't know the club only has 1st gear bush I've ordered the drawings from Rootes archives just for reference .
they don't run on the shaft and are compressed on preload so they come out shorter when you rebuild the box. If they are to short you can't use them .
The gear bore sizes.
1st gear 1 35/64 = 1'5468"
2nd,3rd,and 4th 1 25/64 =1'3906"
The best that I can tell until I get the drawings running clearance is .0035" which seems quite big but it's running in EP80 oil plus there will be some expansion as it gets hot ??
The pinion shaft that the bushes slide on is also a non STD size , they didn't want you to buy these except from Rootes 1st gear 1'2752
The rest are 1'1827". Or 30.04mm so they could have made it 1 3/16 if they had wanted to
I have a spare box so decided to make the 2nd set of bushes from STD 30 x38x30 oilite bushes and 40od for 1stgear theses are cheap and readily available
Turning them between centers on the pinion shaft is the most accurate way to do it .
I used a bore scraper to take out the 30mm to be a good push fit on the shaft then turned of to size
This is still work in progress ?

[PMCG]

Nice work, reminds me of me with the valve body out the Merc. and in bits.

[Gary Whitaker]

Hi the next bit has got me a bit confused pinion tail bearing shims ? I think there may have been a bit of cheating at the factory .
I'll try and explain my thinking . I am from a engineering machining background and sometimes things go wrong but not that wrongly that an expensive part has to be scraped .if you look at the manual it tells you to make up the drop from outer bearing housing to inner to .032" if the drop on the bearing is .0010" then you need .022" of shims , that's a lot of shims .I've measured the bearings I have and the old ones that came out and they are about the same but the first box had .012" of shims but the second box had no shim's at all and there was no way the bearing had .032" of drop on it .
I think they had problems holding the tolerance at the factory , lve seen it before at some places I've worked they go to inspection they are undersize a tags put on -.008" then on assembly they put .008" less shim's in and all's perfect .
So the conclusion is I will put back what came out for the pinion tail bearing and let you know if it works out when I do the preload.
If I was still working I could have measured both boxes on the CMM and seen if there was a difference but I don't have the equipment at home It would be nice to talk to someone that worked at Linwood to see if it happened
Best regards Gary

[John A. Ross]

Gary

There is some folk lore that there was a lot of later transaxles around which were just thrown together out of surplus and reject parts towards the end of manufacturing.

I cant see even rootes/chrysler authorising that potential headache from above.

However i can see a tolerance issue like this creeping in quite easily and letting it slip in. You would spot no shims if needed a mile off but if its tight it would be a lot harder to diagnose it as faulty ?

Linwood tolerances I have seen out by a country mile on rear arm centres, hubs, drums, stub axles are horendous, body shells we know all about so not sure why the transaxle would be any different !

Nice catch though.

Maybe it is as simple as the trnsaxle was rebuilt before and just not done well

John

[Gary Whitaker]

If they were out of tolerance it would be simple to rectify on assembly they would have an abundance of shims available to them, and is that not why the shims are there in the first place

[John A. Ross]

Nothing would surprise me from Linwood expecially if there was bonusses involved for meeting targets

[moose549]

My thoughts have always been all the bearings you buy would be made to a better tolerance than the imp casings???? If you pull a box apart and there are shims in there it is to allow for the tolerances on the casings so, so long as you re-use the same casings and shims it should be right. I do not think changing the bearings would require different shims. If you broke any of the casings (as i have done rallying) and swapped out one section then you would need to shim everything up. Lets discuss

[John A. Ross]

Mike

Imp transaxles ae my nemesis, never had any luck with them so I actually find this discussion fantastic as it lets me see things a bit clearer from a distance.

I always though tapered bearings had a height tolerance that was quite generous to allow for expansion ?

Perhaps now things are better with modern processes but any I have encountered on our machines you would say never have the alignment marks you made on disassembly match up on re-assembly, these were mostly really fine metric threads, yet on re-assembly with new bearing (same part number) you would have +/- a 1/2 turn from where you marked it to get same end floats on the shafts.The manuals aslways saidf mark and return to exact same place but would be contrary to the spcification on end float which was out.

Casing tolerances were likely poor, some may have needed no washer and if preload was OK was just passed as "ok" ?

[moose549]

Doing some interesting reading on what happens to die cast ally when you weld it !

[John A. Ross]

Only comment I would have is welding cast is a PITA and then some more. Depending on the alloy, needs right filler rod, preheat, proper shield gas and if its one of the more lethal mixes a damn good mask. Remember first time I got it wrong (think mistakes sometimes better to learn from ) I started to think it was not ally until the wise one laughing at my attempts eventually explained the loads of different compositions of the alloys and how different they can be as regards thermal conductivity. That was during my testing, it was either wled some cast (which was a setup for me to fail) or go ahead and do some L3 testing but stuff hanging upwside down to weld. Who knew !

Enjoy the research Mike

[Gary Whitaker]

RG370
made copy's of the pinion head bearing and pinion tail bearing fitting tools .
These are simple tools for fitting the taper bearing casing ,as most of you know when fitting there is not much of the casing to tap in usually about 1 mm each side and if you use a socket it will have to be just under the outside diameter of the bearing so as to seat it completely onto the shims ,if you move to one side you could easily hit the side of the housing and damage the aluminium.
The purpose of these tools is to stop that by locating central in the back of the bearing casing and keep it sq
I don't know what the hole is for possibly to just remove some weight.
I've explained it best I can any questions please post Once I've made all the tools if anyone would like a set or just one please get in touch
Best regards Gary

[Gary Whitaker]

RG 369 Input shaft needle roller bearing removal and fitting tool.

Got some time today plus material for the other tools arrived this tool has one end to remove the bearing consisting of a stepped sq shouldered shaft with the OD just under bearing size so you can knock it Straight through
The other end has an angled face so that when the bearing is pressed or knocked in it only contacts OD corner which is the strongest part of the casing,it also has a small step to knock it in to the correct depth, but as the castings vary in thickness and the face is not machined I don't really know how this
works.
The first two pics are the fitting end and last two for removal.
Best regards Gary