Gearbox Alignment

[JRCWeedon]

Hi All (particularly Tom!)

I am sure that I am making heavy weather of this but here goes

Having removed the gearbox I find that the dowell bolts as supplied by Moss will not fit the engine backplate since all the holes are threaded for the normal bolt size. Revington tell me that I need dowells which are not threaded which push in having drilled the hole out to the appropriate size.

So the question is what is the external diameter of these mysterious dowells?

All contributions gratefully received

Regards

John

[Red 6]

Hi All (particularly Tom!)

I am sure that I am making heavy weather of this but here goes

Having removed the gearbox I find that the dowell bolts as supplied by Moss will not fit the engine backplate since all the holes are threaded for the normal bolt size. Revington tell me that I need dowells which are not threaded which push in having drilled the hole out to the appropriate size.

So the question is what is the external diameter of these mysterious dowells?

All contributions gratefully received

Regards

John

Could you be a bit more specific as i am not quite sure what you mean.

 

Along the top of the engine/backplate are 3 studs (screw in). On the flywheel are 3 dowels ("tolerence" push fit) . What i am reading is that you have drilled out the "stud holes" to fit dowels.

 

Please confirm i have miss read this!!!!!

[JRCWeedon]

Could you be a bit more specific as i am not quite sure what you mean.

 

Along the top of the engine/backplate are 3 studs (screw in). On the flywheel are 3 dowels ("tolerence" push fit) . What i am reading is that you have drilled out the "stud holes" to fit dowels.

 

Please confirm i have miss read this!!!!!

 

Hi

I obviously didn't describe it very well!!!

This has got nothing to do with the flywheel but the way the gearbox mates with the plate at the rear of my engine.

All the holes are threaded for the normal bolt size but the "dowell bolt" as supplied by Moss is a larger diameter and will not fit. Those that know about these things insist there should be two dowells opposite each other to locate the gearbox so that there is no misalignment of the gearbox which I seemed to be suffering from. I don't know whether the TR5 is different to the TR6 in this respect but it looks as though I need to get some suitable dowells made up and need the diameter of them.

Hope this is clearer.

Regards

John

[TIMS]

John

 

Have a look at

 

http://web.archive.org/web/20040205235144/...x_technical.htm

 

and at Reliable Clutch. I recall Nelson covers your points in there.

 

Also search the TR6 Forum because it is on there that Tom has posted further details.

 

I have a Gunst release bearing which kit provides the dowels.

 

Regards

 

Tim

[Tom Fremont]

Not wishing to be redundant ( couldn't open Tim's link ):

 

There is a pair of 3/8" diameter holes in the circle, one just above the starter and the other at 180 degrees. This size is unique in the circle as the starter holes are 13/32" and the rest are 11/32". The 3/8" pair was apparently used to pilot the gearbox to the adaptor plate with 3/8" dowel bolts or just plain dowels ( which are now supplied in some kits like TRF's Magic Clutch Kit ).

 

Ignorant of these holes before, I went with 11/32" drill bits in a pair of opposing holes in the circle, pushing them through until the uncut shank passed through both members, then tightened the remaining bolts, removed the drill bits and replaced them with regular bolts.

 

Hence you can either go with the original 3/8" holes or do what I did and get the same effect. I will note that with my latest effort I found the 11/32" holes to be more demanding than the 3/8" ones with dowels, possibly because of wear in the alloy gearbox holes in the latter.

 

Neither choice requires modifying any holes.

 

Hope this helps

[JRCWeedon]

Not wishing to be redundant ( couldn't open Tim's link ):

 

There is a pair of 3/8" diameter holes in the circle, one just above the starter and the other at 180 degrees. This size is unique in the circle as the starter holes are 13/32" and the rest are 11/32". The 3/8" pair was apparently used to pilot the gearbox to the adaptor plate with 3/8" dowel bolts or just plain dowels ( which are now supplied in some kits like TRF's Magic Clutch Kit ).

 

Ignorant of these holes before, I went with 11/32" drill bits in a pair of opposing holes in the circle, pushing them through until the uncut shank passed through both members, then tightened the remaining bolts, removed the drill bits and replaced them with regular bolts.

 

Hence you can either go with the original 3/8" holes or do what I did and get the same effect. I will note that with my latest effort I found the 11/32" holes to be more demanding than the 3/8" ones with dowels, possibly because of wear in the alloy gearbox holes in the latter.

 

Neither choice requires modifying any holes.

 

Hope this helps

 

 

Thanks guys for the helpful info (as always) I should be able to sort it now.

Regards

John