• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

TR2/3/3A TR25- Differential Question

Share this page

glemon

glemon

Yoda
Bronze
Country flag
Offline
Supposed to be TR250, fat fingers can't figure out hwo to edite the topic heading.

I traced a noticeable on throttle off throttle little squeeky kind of noise to the rear pinion flange/seal bearing area in my TR250. I replaced the seal there last year and thought I had gotten everything back together right.

When I took it apart the cotter pin had come out of the castellated nut that holds the pinion flange in. The nut was not on very tight.

As I understand it on the early cars the bearing pre-load is set by shims and the tightness of the castellated nut is not so critical.

There is some play vertical in and out of the tailshaft even if I tighten the flange down all the way, no side to side play, is this normal/ok? I really don't want to pull the differentail again for the next ten years or ever if at all possible, everything is looking and sounding ok, and it stopped squealing for now but I don't want to just band-aid it and tighten down the castelleated nut and put the cotter pin on right this time, and then have it act up on me again.

Measured the movement, it is about .002" the seal looks to still be in good shape

The squeek seems to have gone away, I was driving a lot on dirt right before it started, but if something was stuck in there I would think it would squeal all the time, not just when sudden rotational forces were applied.
 
If you have the castellated nut, it is a pretty safe bet that the pinion has the solid spacer and the preload is set with shims. The collapsible spacer came much later and used a nylock nut. Sounds like you may have other issues if the pinion has movement with the nut tightened-there shouldn't be any. Removing the diff is painless on the 250s and early 6s with the single pipe exhaust compared to the later cars with dual pipes. Another possible source of a squeak is a rt front diff mount pin that has broken away from the frame. Berry
 
Are you saying that you can feel the input shaft to the differential move vertically? That sounds like a serious problem to me; both because something must be broken inside and because the moving shaft will upset the mesh between the gears.
 
Thanks, I have a custom dual exhaust, so the back part of that had to come off too, I don't think it is the diff mounts, I could see and hear the noise corresponding to the flange moving, but I had planned on doing a thourough check of them this summer anyway, and will probably gusset them regardless of what I find.

Greg
 
Randall, missed your post, if by vertically you mean towards and away from the motor or in the more recent vicinity the driveshaft, yes, vertically, it seemed like more but when I measured about .02"
 
Well, I think I did the right thing in taking out the differential, regardless of what I need to do to it, I said I wanted to inspect the differential mounting points and the front right is cracked all the way across just behind the pin. I did do an electronically timed 16.61 second quarter mile, and consistently ran around 16.7 right before the dismantle, not too shabby (stock was 17.8), but I guess I little racing around can bust your parts up but good, actually it may have been broken before that, I did hear an occasional clunk back there (was planning on pulling the diff anyway to check) before I heard the consistent squeak that I started this post off with.
 
Last edited:
Yup. Driving them hard is a lot of fun; but can definitely lead to broken parts.

 
The rest of the story. I took the diff out, one of the diff mounts, right front was cracked all the way across, this was making the noise I attributed to the diff (squeak squeak on and off throttle at low speeds). All braced and welded up and fixed now. I took the diff to shop which still has what I call "old timers" guys who have done what they do long enough to remember when Triumphs roamed the earth, and who have more resources in their shop and minds than looking whatever up by year, make and model in the computer, trusted shop with a lot of experience, they checked the play, listened to the sound and felt the rotation, pronounced it fine, said they would tear it apart and check it all out if I really wanted, but it would be close to a days work. I decided to pop it back in, all seems fine so far.
 
Back
Top