TR4/4A TR4 Starter Rebuild Questions

Had a starter failure on a club drive yesterday -- tested as a dead short in the unit. Pulling it apart this morning I saw what I expected to see, the wrapping on the field coil had worn thru in a couple of spots -- this is likely the one that did me in:



Ooh that's ugly. Having gone this far I think I will try my hand at re-wrapping them. I have a roll of friction tape (hockey stick tape to those in Minnie-sooota) which I may try to cut in half (width wise). I know I don't want to build up the thickness much, just cover the winding.

Any of you done this? Friction tape sound like a reasonable thing?

Second question -- I'm thinking I should renew the bearings while I'm at it. In particular the front one seems to have some slop. I was expecting the armature to simply slide out then I would press out the bearing...



...but the armature doesn't readily move (other than a 1/32" movement front-to-back). Does it also get pressed out? As for this and the bearings -- is it reasonable to do this with a vise and a couple of sockets or whatever or should I not even attempt this w/o a press?

Note: I'm not interested in putting in a hi-torque starter, thanks for any other advice.

I haven't done any starter rebuilds (only generators), but this was one of the first problems that I had when I got my TR4A. Took it to a local autoshop which still had a very old school guy that rewrapped the field coils for me. Charged a whole $18!

I'm very interested in hearing how you get along with this.

Scott

It looks to be the same as the TR3 starter. I know I took mine apart, because I had an ebay starer with a broken case, and the one in the car that was under 20' of salt water. I swapped guts/case and it now spins when I supply 12v. I don't remember having trouble pulling the case end off the armature. I may have used two lengths of all-thread to a bar on top the end of the shaft to get it started, but I think it should just slide off.

Perfect time to install a new gear reduciton starter.... (ducks for cover)

Not sure what the deal with the armature is, Geo, it should just slide right out. But I don't think it would hurt anything to put some force on it. Worst case the bearing would come out, where you could cut it off the shaft & view the damage.

Bench vise should do fine for changing the bushings, that's what I used (many years ago when I had a TR3A with the later starter).

And friction tape seems fine for wrapping the windings. My only concern would be if the obvious heat (from the short) has damaged the insulation between windings enough to allow an inter-winding short (now or in the near future).

You may want to coat the windings in the damaged area with conformal coat prior to wrapping them with tape. Conformal coat is a clear liquid used to coat circuit card assemblies to prevent moisture damage. You can probably pick it up at Radio Shack.

Thanks for all the info, advice and offers of used starters -- you guys are great.

Got it repaired, put back together and everything works perfectly. That wrapping seemed to remind me of something...



3 things for the benefit of future archive searchers:

1. I was using the Haynes manual (I like the challenge of vague instructions) -- would have been nice if they had mentioned that the nut on the front of the shaft is left-hand threads. I figured it out pretty quick though.

2. I did not replace the bearings -- decided they were not too worn, that I was sensing drag rather than slop. I recalled you soak them in oil for 24 hours when replacing them. Since they had been on the job for 45 years I'm guessing that original lube was long gone so I rigged a set-up to soak them overnight in oil in situ. Much smoother action now.

3. Thanks to whomever (Randall I think) once suggested putting the top mounting bolt in from the rear of the flange so you can easily thread on the nut. Actually, he may have suggested threading the case for a stud there -- but anyway it got me thinking and made the re-install easy.

Did this last time I replaced the starter.

Since I have a later TR6 case with the thicker flange, I just threaded the flange for a Helicoil. Works slick, IMO.

I had a ground between the field (stator) windings and the inside of the outer barrel of the starter from my early 1958 TR3A. The 50-odd year old insulation had scrubbed through. I know my starter is a long bullet-nose type but the same could apply for any TR starter. I unscrewed the the huge screws and removed the stator windings and laminations then used sticky electrical tape and re-insulated the windings, right over the original insulation (or what-ever was still there) and re-assembled it all. It ran on the bench connected to my spare battery but it wouldn't run when I put it back in the TR. So I took it all out again and took it to a local shop who repairs starters etc. It seems that the thicker insulation moved the laminations closer to the armature because of the extra thickness of the new insulation and the stator laminations were rubbing on the armature preventing it from rotating. Luckily, I had taken him a spare body with good stator windings and this worked fine. The local shop where they did the final re-build and test for me charged me $30.00 (CDN$). That works out to about $28.00 US.

Geo Hahn said:

2. I did not replace the bearings -- decided they were not too worn, that I was sensing drag rather than slop. I recalled you soak them in oil for 24 hours when replacing them. Since they had been on the job for 45 years I'm guessing that original lube was long gone so I rigged a set-up to soak them overnight in oil in situ. Much smoother action now.

Click to expand...

Geo,

Are either of these Oilite bushings like the rear bushing in the generator? Oilite bushings definitely need to be soaked 24 hours in oil (I would soak mine in hot oil). Not sure I've heard that for bearings though. Good to know if that's needed for them as well!

This was the biggest problem I had with local shops rebuilding Lucas generators as I'd have them fail with less than 10,000 miles after the rebuild and the issue was always wear in the rear bushing. After I started rebuilding them myself, I stopped having generator problems. 60,000+ miles on the 2 that I finally did myself.

Scott

Boy, you're lucky you could get the field windings out of the case.
My starter did that, except some TURKEY spot-welded the screws in.
I could have drilled them out, but then I'd have had to find new screws.........used starter was easier (still have the old one....someday)

HerronScott said:

Are either of these Oilite bushings like the rear bushing in the generator?

Click to expand...

Yes, exactly.

I've got a 6 starter I would like to give away. Tested and works after it's been cleaned up. Installed on car then removed during it's sit.