Starter Motor Problems

[Dic Doretti]

          I recently fitted a 4 synchro o/d gearbox to my TR2 along with a later flywheel and starter motor. I have not used the car very much and the starter has stuck in engagement, it was being driven by the engine. I tried the usual solution with a big hammer but no success so after a struggle I removed the starter motor and the pinion teeth look stressed so I wonder if the number of teeth is correct, there are 10. Any help appreciated.

          Cheers

          Richard

[RobH]

10 teeth is correct for the later flywheel with bolt-on ring gear.   The earlier shrunk-on type needs 9 teeth. 

[Lebro]

+1

Bob

[Dic Doretti]

          Thanks Rob and Bob, further research required as to why it jammed, the teeth are certainly marked.

          Cheers

          Richard

[jerrytr5]

I have seen starters fitted with shims on the mounting flange thus altering the throw of the pinion. I don't know how you would measure and select the shim thickness.

Jerry

[BlueTR3A-5EKT]

Which style of bendix gear is fitted to the starter?  
Full length tooth or half length?  

Half length is correct for original TR fitment.  

The full length type is from a commercial vehicle and is often fitted.   My question is why did Lucas and Triumph decide the half length gear tooth type was correct for the TR engine?

PS I think I have a NOS Triumph type bendix gear in the spares box if you get stuck.

 

 

Edited July 21, 2023 by BlueTR3A-5EKT

[Z320]

Hi Richard,

shure you know the Bendix mechanism mustn't be greased for a proper engage and disengage.

Perhaps you know both of my 2 videos about how it works on Youtube from 2012?

I used a M418G with a full sprocket without any problems on my TR4A until I had to swap to a high torque starter because of my MX5 gearbox.

Also "a half sprocket" should work (I got such a starter as a spare part) because the toothed side is to the flywheel, the difference is the weight.

The starter has to be shimmed correctly, I've been told years ago the "out of mash clearance" should be about 1/8".

Knowing this I let the one out that I found fitted. Sadly the workshop manual tells nothing about this.

One shim more reduces the clearance, one shim less gives more clearance.

With the gearbox still in - and the starter out - you can messuere and calculate the clearance:

Lenght from the starter flange to the starter sprocket ./. depht from the engine flange to the toothed ring on the flywheel.

A bit tricky to get there, even more on a RHD TR. Wishing you much success.

Ciao, Marco

Edited July 22, 2023 by Z320

[Dic Doretti]

          Thank you everyone for your help. The starter motor is back in place and fingers are crossed. The bendix was damaged and the pinion was sticking but I could not tell if this was the cause of the jamming or the result, it was fine when fitted during the winter. I have several decrepit starter motors lying around so I cleaned up the best bendix and fitted that and so far it is working.

          I took a starter motor off a 1965 Mustang last week which took less than 5 mins unlike the struggle with the TR, the bellhousing was threaded. When I refitted the starter motor I captivated the nuts and used allen headed bolts which made the job a lot easier apart from the exhaust.

          Cheers

          Richard

[Lebro]

Nice solution.

Bob

[Z320]

This is a nice example about

how different people have the same challenge and come to the same solution