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TR5/TR250 Trans slipping in reverse

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tinman58

tinman58

Jedi Knight
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I have a recently rebuilt transmission. Works fine, except when in reverse I get a slipping (not clutch). The transmission guy said it sounded like the rear hubs. The diff was leaking gear oil so I pulled the axels and the diff out and took them to a shop to be checked and rebuilt if needed. I still don’t understand how slipping could be from the rear end. Tranny guy also said that 1st and reverse are on the same shaft so can’t be transmission. What am I missing?
 
I think they meant the rear wheel hubs rather than the differential. Do you have wires? The wire to wheel hubs can also slip.
 
I have both. I like the rostyle caps and my wife likes the wire wheels. It slips with both. I don’t understand how the hubs can spin.
 
Hub slipping ???? Splined hubs if it slipped one time that is one time to many. Question??? With rear on jacks and EM brake set can you turn either rear wheel you may be stopping on front wheels only (very bad idea ) These splines are very fine and ounce rolling you would not feel a slipping wheel. Starting in first and lower Rev. will slip as load is heaviest. This can happen with lack of service rust very hard driving. I would tell you to go on a empty road and hit brakes hard. most TR will not lock wheels but you may not stop very well. OK do not try this at home you need all new hubs and rims through in new tires too. I have only seen this happen on Jags that are much heavier cars. Madflyer
 
Mad flyer , it only slips in reverse and with the steel rims. Splices on the set of wire wheels are in great shape and pretty new.
 
(Tranny guy also said that 1st and reverse are on the same shaft so can’t be transmission)
1st and second are on the same selector shaft,reverse is on its own selector shaft,
phil
 
I guess we do not under stand slipping do you mean it will not go backwards?? The bell crank to shift into REV may have been mist when cover replaced. Madflyer
 
The reason I asked if the trans. has OD is that the cone clutch in the OD transmits the power in reverse. If the inner linings on the clutch are worn or the clutch isn't functioning, it will slip in reverse.
Berry
 
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Is it just a slip, or is it accompanied with a grinding or ratcheting sound? Also, OD or non-OD tranny?
 
I do have od. There is no grinding or other noise. It is just like maybe half the power is transmitted to the rear wheels. If backing up a steep driveway it seems worse. So could be overdrive. The rebuilder of the transmission was not a Triumph Guy. He said a transmission is a transmission. I should have had a Triumph mech do the rebuild!
 
Well, if you have ruled out the clutch...and there is no grinding, which would mark a bad gear, hub sprocket or wheel sprocket.

Then I am afraid the OD is next. You very well may be stuck in OD, and you can damage the OD sprag clutch trying to go in reverse. There is no reverse in OD, so the sprag clutch attempts to prevent reverse movement of the car. If forced, it will shatter the sprag. Most who have tried to reverse with the OD stuck describe reverse as "hitting a curb" feel. If you are lucky, your sprag is slipping, rather than locking and shattering.

I used straight non- detergent 30w in my OD, as the book recommends when I rebuilt it. The OD would stick engaged until I took a wrench and wacked the OD bell a few times. I switched to Red Line MT90 and the sticking immediately stopped. So...

Try tapping the OD bell and listen for a "ding" as the OD ring snaps back. If that does not help, then check the solenoid adjustment to make sure it is allowing the OD to disengage. Finally, make sure you switch to Red Line RT90. I think one of those will get you going.
 
I have been driving the car for about four years. The overdrive works as should be. Pops in and out no problem! I am using valvoline 20-50 in the transmission. Just flushed and new oil no change, probably have 5000 miles on the transmission. I don’t remember if the slipping was there before the rebuild.
 
This is an unusual one, I like it. This is a curve ball and a big guess, but so---anyways is it possible for a rear brake shoe to slip down and only be effective and drag in reverse?
steve
 
I think the springs that hold the clutch in direct drive would be at the top of the culprit list. They tend to weaken with age. But only an autopsy will tell.
Berry
 
tinman58 said:
I have been driving the car for about four years. The overdrive works as should be. Pops in and out no problem! I am using valvoline 20-50 in the transmission. Just flushed and new oil no change, probably have 5000 miles on the transmission. I don’t remember if the slipping was there before the rebuild.
Click to expand...

All your descriptions still point to an issue with the OD. Anything else but the engine clutch would make grinding sounds. Detergent motor oil is not recommended in the OD, as the sun gears spin so fast they can foam the oil. I still highly recommend the MT90.
 
Just thought of one other possible problem...the engine clutch disc. I have seen very cheap discs where the center is not properly attached to the friction disc...but usually they let completely loose and have no drive at all. OD is still the most likely issue.
 
Thank you all. I think that I will remove the transmission and OD and have it checked out. I am glad that I invested in a car lift.
7C4F9C2B-C526-491C-918B-13A22B44DB0D.jpg
 
Just found this on Buckeye Triumphs! In the trouble shooting section
OD slips in direct drive (reverse): If the OD slips in direct drive in the reverse direction, then the sliding clutch is likely slipping in released position. The most likely cause of the slipping is weak clutch release springs. Another possibility is a damaged clutch sliding member. Wear of the clutch material is unlikely since the load on the clutch in the rear position is very small relative the forward position so any wear problems would likely show up in the forward position (OD engaged) first.
 
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Things in agreement straight weight non det. oil SAE 90. If it moves in REV. then not gear box REV idler. leaves two clutch disk and springs in OD. Clutch B & B cheaper unit as to LUK is better unit. OD A or J ??

Call this guy if you want a TR trans guy. Ray Marty Gales Creek Or 503-357-5640 Say Andy sent you Reno NV. Madflyer
 
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