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overdrive main shaft ID

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BOXoROCKS

Jedi Knight
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I have an O/D mainshaft that I believe to be from a TR250 A type along with the adapter plate and speedo pinion, a fellow has emailed me saying that I am incirrect and that it is for a TR3 non syncro...the problem...how to identify the shaft..there is absolutely no markings on this shaft, and Moss says my adapter is correct...any ideas? I am not sure how to post a photo
 
a pix I hope
 

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Can you take a picture of the other side of the adapter plate? The mainshaft doesn't look like the other A-type overdrive mainshafts for TR4-early TR6 or the later TR6 that I see posted on eBay or Quantum Mechanics website.

Scott
 
Does look like a 3-synchro shaft to me. The big splines in the center of the gearbox section are much shorter and lack the middle groove for the 4-synchro versions.

Here's the illustration from the TR3 SPC:
 

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And the TR4 version (which should be similar if not identical to the TR250):
 

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Here's a photo of the mainshaft and both sides of the adapter plate. These are from my TR4.

I hate to contradict anyone on the forum, but I think it needs to be mentioned that the 2 drawings above show non-overdrive mainshafts. Notice the speedometer drive splines. These are not on OD mainshafts because the mainshaft is not part of the final output drive. On OD units the speedo splines are on the back side of the annulus shaft.




https://s1206.photobucket.com/albums/bb460/celtictwo/?action=view&current=ODShaft1.jpg

gary
 
Yes, I believe that is a 3 syncro mainshaft. Here is the one I have out of a TR3A:
IMG_0176.jpg
 
thanks all, it looks like I bought the wrong parts years ago...good thing I never tore apart my trans to install them. After seeing the difference I can see how yes it is easy to tell them apart
 
Celtic2 said:
I hate to contradict anyone on the forum, but I think it needs to be mentioned that the 2 drawings above show non-overdrive mainshafts.
Click to expand...
No contradiction at all, Gary. You are quite right, those illustrations are for non-OD mainshafts. I put them up only to illustrate the point I was making about the gearbox end of the shaft (which is the same whether there is an OD at the other end or not). My apologies if that wasn't clear.
 
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