Southern GT #70

Davidmgbv8

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Yeah but I do not want 4 separate spinners so we will try to cut down the rear spindles to match, or that is at least today’s plan. I never knew how intricate it was to make threads.
 

Davidmgbv8

Supporter
Put the front suspension together and aligned but the front wheels rub on the front edge of the front fenders. I am at 95” on the wheelbase. 4 degrees caster, .6 camber. 1-1/16 toe in. Any ideas?
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Davidmgbv8

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We got the new bearings on the me ATB. Back lash worked out perfect. What was less than perfect was the 5th synchro and the lack of proper bearings for the larger Quaife mainshaft. So moral of the story, buying used gear stuff or transaxles, do a huge amount of research first!!!!
 

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Randy V

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On my RCR, I needed 6+° caster to get the wheelbase to 95”. Can you move the upper control arms towards the rear of the chassis or shim them to accomplish this?
 

Davidmgbv8

Supporter
Well I have learned my lesson on this whole transmission thing now 4x over. First making the mistake of not purchasing already done up and shipped with my chassis. Second, buying a second hand 369 from someone taking out of their car and swapping in an Audi box... maybe there was a reason they were upgrading, you think??? Third trying to save some money by buying a "slightly" used one piece Quaife main shaft and gears only to find out I did not get bearings with it and the 5th syncro dog hub on the mainshaft is very worn. GTO just does not sell separates.... Working on options with Kevin at GTO, he is very helpful. Moral of the story. Figure out your transaxle first, don't buy used stuff and get your transaxle all done up to your power specs by a professional that has the experience....

Now going back in time to kick my ass a little...
 

Brian

Supporter
You know, that doesn't look like wear to me. It looks like an intentional undercut. It's intended to try to pull it into gear under pressure rather than kick it out. I may be wrong, but I can't see it wearing there and like that. Worn blockers have the top V all mushed and rounded.

Again, not a gearbox expert here, but if that was wear it would have happened when all the way engaged, not from syncing.
 

Brian

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Don't go on just my untrained observation, but if it's wear, it's from millions of miles in 5th rather than gear jamming.

For me, if I had the option of buy a different transaxle and scrap that one, or run what you have until it breaks, I would maybe clean to top burs and run with it unless you can find a new one. I would only consider cleaning the burs off so they don't clean themselves off and float around wrecking other things.

It could be from real high mileage, but I think I see an intentional taper like they cut into dog boxes so the pressure is pulling it into engagement rather than if it was square or sloped the other way and being neutral to pushing it out of engagement.
 

Davidmgbv8

Supporter
To be clear, this is a Quaife 1 piece gear shaft and gear set. All the other gears that came with this do not have this kind of wear. Now the difference between this gear and the one that came in the UN1 transmission is the shaft diameter. I can get new gears no problem. The new shaft is much larger diameter and the old gear, which is in fine shape, will not fit. GTO racing suggested I take and get EDM machined out and I took it to a shop today however they will not do the work unless they have a drawing. Kevin is going to contact Quaife and see if they will supply a redacted drawing with the dimensions I need to take to EDM. Unfortunately, Quaife will not sell just the gear I need they want to sell the whole set....
 

Davidmgbv8

Supporter
So here is what I did to tonight.... I took a Dremel tool with Diamond bits and with magnifiers on carefully took off the metal that was raised and overlapped. Then I put in the vibratory tumbler for 2 hours, then cleaned and polished the surfaces on the buffer. It is far smoother now and while I realize the metal was moved from the side of the tooth up, I am in favor of using this dog hub engagement. Is there any reason why I should not??

I need input from you guys with UN1's and or other gear box experiences.


Many Thanks
 

Randy V

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That was a lot of wear…. Cause?
- extreme loading?
- poor heat treating? (I would suspect that if the slider is in good shape)
- poor or lack of lubrication? (Although it doesn’t appear to be discolored]
—-
You may well “get by” with your clean-up, but it won’t be as strong as it once was.
Possibly consider re heat treating it?
@jac mac - what say you?
 

Davidmgbv8

Supporter
Since I bought just the mainshaft and gears as the guy was changing to Albins I have no idea what the other bits looked like.. Kevin said it may be improper shimming and it was trying to "pull in". He suggested when we go back we may need to add a .005 or .01shim
 
That was a lot of wear…. Cause?
- extreme loading?
- poor heat treating? (I would suspect that if the slider is in good shape)
- poor or lack of lubrication? (Although it doesn’t appear to be discolored]
—-
You may well “get by” with your clean-up, but it won’t be as strong as it once was.
Possibly consider re heat treating it?
@jac mac - what say you?
Brian in post #170 has it right, the internal splines in the sliders will have a taper cut to pull it into gear, it is not wear so much as a 'plastic' deformation of the dogs on the gear to match with the taper in the slider. Grinding the parts to remove the pushed up area's was quite common back in 60/70's on most manual trans of that era- Muncie, T10, Top Loader etc. Like you have mentioned somewhat delicate job & you might only get one go at it. A bloke by name of Pepe Estrada was where I first read about it being done.
 

Davidmgbv8

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Good info Jac Mac. So I have most of the deformation on the top off and smoothed. Do I just reinstall once I get my bearings or heat or Cryogenic treat before I reasseble?

Thanks
 

Davidmgbv8

Supporter
Tonight I test fitted exhaust pipes. I learned my gasket was junk dropping 1/8” below top of port and at bottom 1/8 below the port. The fancy stainless ARP 12 point bolts are near impossible to install and I will look for Allen heads next… oh and the pipe 6 and 7 have a mind of their own. 7 likes to install prior to 6.
That is all
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