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TR5/TR250 Transmission # ?

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tinman58

tinman58

Jedi Knight
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Last Saturday we went to the British car show ia the Blackhawk Muesum. Great show ( we took first place in our division) .
The transmission was pretty sad. I did not go thru it when I restored the 250. (Big mistake).
One block from home first gear went CRUNCH! I was able to get home in second gear.
All the other gears work fine. When I drained the trans fluid small pieces of what looks like a needle bearing came out. Not good. So I pulled out the trans and took it to our vintage trans shop. He did not seem to optimistic. The number on the trans is CT 65195. I know that the engine is from a 72 TR6. I cant find the prefix CT anywhere. I want to make sure i get the right parts for the rebuild. Any body know where i can find more information on the trans numbers?
 
Thank You Charley
The TR4 transmission with a TR6 engine, Could the extra 2 cylinders ruin a trans? I guess i should find a good TR6 transmission.
I am noe think about the HVDA conversion , I have that on my TR3
 
Dan, I have a good 250 gearbox but I'm in Maine. Non OD but AFAIK in good working order. I purchased from a guy that was putting a big V8 in his 250.
 
I do not think using a 4 cylinder TR gearbox in a 6-cylinder TR would be enough to cause any issues.

I don't know what a gearbox rebuild costs but I would certainly consider a rebuilt unit with OD from John Esposito (Quantumechanics) among the options.
 
Years ago, before Al Gore invented the internet, I had to locate a trans for a 69 TR6. All I could come up with was out of a TR3 which was sold to me to be "the same transmission" ( which we all know is not accurate ). We were, however, able to use parts from the TR3 transmission to rebuild the TR6 transmission. So, they are very similar. Point being, I don't think the TR4 trans would be too weak for the TR250 6 cyl.
 
I believe the only differences between the internals of the two trannys is some of the bearings. Of course those would be to take any extra wear caused by the bigger engine. I suspect that most authorities believe there is little difference in their ability to take the load. Actually even the Stag transmission is very similar to the TR6 tranny and that would be for a V8.
Charley
 
+1. There were several upgrades from the early TR3 transmissions to The TR250 and TR6. It would be nice to have those upgrades, I suppose, but not necessary. Assuming yours is non overdrive, I don't think the latter transmissions are that scarce.
I would simply rebuild the one you have and if your transmission expert can't do it from the CT number, perhaps get another expert. Of course you could also him go go through one like PeterK's instead.
As for a OD rebuilt from Esposito, good idea but I don't think your core, without OD, would be of much value. I'm sure there are rebuilts available on the West Coast too.
Tom
 
charleyf said:
I believe the only differences between the internals of the two trannys is some of the bearings. Of course those would be to take any extra wear caused by the bigger engine...
Click to expand...

50% more cylinders but the displacement went from 2138 to 2498 - a 16.8% increase. Not a huge bump, all things considered.
 
I do have the a-type overdrive. Would it be worth to get a TR6 trans and rebuild it? Or should i just rebuild and up grade the TR4 trans? I don't want to be without the 250 for a month or more.
 
Have you considered buying a 1970's Triumph 6 cyl sedan OD gearbox and having it checked out before installing.....We had lots of sedans here in Australia, do not know about the USA....or converting to a 5 speed gearbox eg.toyota.[ I can put you in touch with a friend of mine in Toronto that has done the conversion on his 250 ].
 
tinman58 said:
I do have the a-type overdrive. Would it be worth to get a TR6 trans and rebuild it? Or should i just rebuild and up grade the TR4 trans? I don't want to be without the 250 for a month or more.
Click to expand...

I'd call around for an exchange unit, by far the fastest way. I think your OD TR4 unit will be an acceptable core so check on that. Here's from google for comparison, I have no knowledge of this company, perhaps you can find something on the West Coast: https://www.wishboneclassics.com/content/rebuilt-tr250-tr6-transmission-w-j-type-od

 
Even if you farm the work out, here is a great article about rebuilding the TR trannies, including information on the differences, which as noted are not that great, but as I recall upgrading to newer spec is a little more complicated than just swapping out older bearings for new style.

https://vintagetriumphregister.org/maintenance/ scroll down
 
I just found a 1971 engine and 4 speed trans for $650. What is the work involved to install the a type overdrive on the 4 speed trans? Approx 23,000 miles on both.
 
I tried to do it, and the tranny worked for a while, but then wouldn't shift into 2nd gear. I work on most anything except trannies and diffs. If you pull the tranny yourself it doesn't cost as much for a professional rebuild.
 
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The correct trans for your 250 should be CD XXXX. it would be between 200-300 higher than your commission number. As far as repair is concerned, it's doable. I've built 7-8 gearboxes and 4 of them have been ODs. There isn't much that requires advanced knowledge or special tools. If you were closer I'd gladly lend a hand. PM me if you want to chat about it.
 
This is what I found in the bottom of the drain pan.
IMG_4339.jpg
It looks like what is left of needle bearings. Also there was a LOT of metal shavings.
The transmission guy still hasn't gotten to the tear down yet.
 
Are they needles or teeth. It almost looks like flats on them when I zoom in on the photo. Whatever they are it is not good.

David
 
needles
 
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