• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.

    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

TR5/TR250 Trans slipping in reverse

Dan, before going to the trouble of pulling the unit, I would really try some Red Line MT90. Geo, Randall, and many others recommend(ed) it. Like I said, my car stuck in OD for weeks, but one trip with MT90 solved the sticking problem. Yours is the opposite, but it is still the same part at fault. If it doesn't work you are only out about $10 in oil.
 
Yup! I am going to try the oil and see what happens. Going to the rear end shop now. They replaced the bearings and seals. Thank you all for the advice, and of course we all miss Randell"s input!
 
Hopefully, the generic trans./shop didn't cause the problem because of not being familiar with the OD. Please let know what caused the issue. Changing the oil can't hurt, but I doubt if it solves the problem.
The Buckeye article is what sparked my response to your posting. There are a real treasure on all things trans./OD.
Berry
 
Last edited:
This is 100% a slipping unidirectional clutch. I actually got my car to do this when i set up the solenoid height too high and the internal ball was not totally seated allowing pressure to build in the OD when turning and cause the slip. Yes the clutch springs will get weaker over time but if the ball is not seating properly it will allow pressure to build in the OD and push on the clutch. As long as that valve is closed the springs are not part of the equation, especially if the OD releases properly when driving.
 
This is 100% a slipping unidirectional clutch. I actually got my car to do this when i set up the solenoid height too high and the internal ball was not totally seated allowing pressure to build in the OD when turning and cause the slip. Yes the clutch springs will get weaker over time but if the ball is not seating properly it will allow pressure to build in the OD and push on the clutch. As long as that valve is closed the springs are not part of the equation, especially if the OD releases properly when driving.
That is certainly a possibility. I hope that Dan checks the operating valve adjustment and drives the car before pulling the trans.
Berry
 
As soon as I get the ear end back from the shop and install it I will fill the transmission with the proper mt 90 oil. Then give it a test run. I was promised the rear end by today but no call, I guess Monday will have to do.
 
Redline is great and I use/recommend it to everyone with OD. Redline absolutely will fix a sticking sliding clutch but the rollers in the spring clutch act steel on steel which sees less impact by oil choice. The actual sliding clutch is lifting off the rear annulus and allowing the rotation.
 
Went to Napa O'riely and the local auto parts store to get the redline oil. No body carries it. Ordered a gallon from amazon, will be at my door tomorrow. Installing the diff. today and brakes flushing out the old brake fluid while I am there.
 
Yes I had the same problem with the red line here in a kinda big city. I have not run my OD yet so I did not order any Red Line, and sorry to be so petty, what does a gallon cost with shipping.
Thanks steve
 
Steve $61.50 from Amazon will be delivered tomorrow.
I reinstalled the rear end today. CFDC9D1F-7846-490B-92C9-DEE177485F2A.jpg I noticed that one of the universal joints was binding a little. Ran down to Napa auto parts and got another one. Installed it on the yoke and axel, (the one near the diff) and the new one is binding also. Ordered a new yoke and universal joint from BPNW, just going to replace it and hope for the best.
 
Took the 250 out for a drive yesterday, the transmission is very smooth with the Redline mt90 oil. Unfortunately the overdrive still slips in reverse....... but at least I know where the problem is. No more leaks from the diff. I think I will just live with it for awhile.
 
Sorry it didn’t work, but at least you’ll never have to wonder if it would have.
 
Well I had the overdrive rebuilt, when I removed the old from the trans there was only 4 springs not 8. I have no idea where the other 4 went. Possibly the guy that rebuilt the trans did not install all 8. He was an old car classic rebuilder. Not a Triumph guy. My mistake. There was a few other things wrong that was found during the inspection. All fixed like new and very happy with how it works. I am glad I didn’t go for the 5 speed swap. Of course while I was there I replaced the heater core and fan motor. New led bulbs in the dash and fixed the loose wiper cable. Just because I had the time i replaced the timing cover seal. So far after about 100 miles no leak. Can’t wait for the weather to warm up a little and do some mountain driving.
 
Back
Top