Triumphrat

Mojoinco · 03-02-2006

O got to thinking (it hurts, and may be detrimental too all), the sprag clutch that I have seen write ups on for being extremely expensive to repair.

What years and models have this, and which years have the improved model?

Is it just the clutch basket asembly, or are there more parts required to get the improved basket to work?

Mojoinco

parrycm · 03-02-2006

Stan and I both did ours and we have 95's. But I've heard of it happening on later years as well, although I would have thought anything past 2000 should be OK for sure.

The replacement sprag is a heftier item than the original fitted on our bikes, but I don't know when they started fitting it from new. If I were to guess I would say around 97-99.

The sprag is not related to the clutch basket at all, and lives inside the engine. The clutch basket is right underneath the clutch cover - the big one on the RHS.

You can see pics of it in my album - clicky beneath my signature.

cafetbird · 03-02-2006

'95 and early '96 ONLY. After that, it was upgraded.

Other people have abused anf fried their sprag clutch though!

GeoffE · 03-03-2006

Hi,

I have always wondered where the production break was for this problem. I have a March 1995 Thunderbird.

Based on the information above, and looking at the parts fiche I have for both the T-Birds and Sprints, the T300 models from Vin# 23707 were fitted with a revised clutch basket assembly.

My Thunderbird has a higher Vin# (24nnn) than this break point, so if "younger" (e.g. '96) bikes had this problem then I suspect this date relates to when they were registered rather than the date of manufacture.

How does this sound? T300s upto Vin#23706 potentially have a sprag clutch problem, and T300s from Vin#23707 should have the uprated parts?
What do you think?

Geoff
:wink:

*** UPDATE: Ah, I can see the Sprag Clutch within the Alternator & Starter Drive Gears. Again the sprag clutch assembly was changed on the Vin 23706/23707 break-point. However BOTH were subsequently replaced by a new Sprag Clutch Assembly - unfortunately there is no mention of when the new assembly applied, only a reference to see Service Bulletin 194.
Does anybody have Service Bulletin 194?

[ This message was edited by: GeoffE on 2006-03-03 10:40 ]

CCR · 03-03-2006

Are there any diagnostic tests for determining the qualitly or lack there of, of your sprag clutch? I've got a 95 tbird, was completely unware of this situation. Money is the last thing I got, but if it'll save me more money down the line I'll work things out. So basically, how do I check to see if its on the way out, or is this just a bum part that should be replaced? I bought the bike with 12k on it, would it have shot already? I hope someone will tell me I'm safe, but thats just youthful optimism.

parrycm - where did you pick up the saddlebag braces? I've got bags from an old bike that I think will work, I just need something to rest them on. Has anyone made these?

Mojoinco · 03-03-2006

The reason I asked is that someone is parting out a Tiger transmission mainshaft with the clutch basket on ebay. I have a 2003, so it sounds like it is of no particular interest to me.

Still interested in the discussion though.

Mojoinco

Mojoinco · 03-03-2006

Alright, just reviewed the sprag pictures. Is the sprag clutch there as the starter release clutch (overspeed release when the engine starts)?

jimmyj900 · 03-03-2006

Quote:

Alright, just reviewed the sprag pictures. Is the sprag clutch there as the starter release clutch (overspeed release when the engine starts)?

Yes, it disengages the starter motor when the engine starts running.

There were apparently three models of the sprag clutch, with the 95-96 model being the smallest and most vulnerable and the 99+ model being the current design. The 99+ sprag requires modification of the engine case to fit the earlier engines but will work.

The major enemies of the sprag clutch seem to be weak batteries and poorly running engines. A weak battery means extra cranking time and stress while a poor-starting engine will kick the sprag in and out, so the key to sprag survival is a well-maintained bike.

Jim

SWare · 03-03-2006

Quote:

On 2006-03-03 08:17, Mojoinco wrote:
Alright, just reviewed the sprag pictures. Is the sprag clutch there as the starter release clutch (overspeed release when the engine starts)?

You got it.
It uses metal roller bearings that will only allow rotation in one direction. When worn the torque from the starter will make the bearings slip instead of cranking the motor over.

stan

parrycm · 03-03-2006

CCR....

Don't worry about the sprag until it actually starts being a problem. I've got a mate that has a 95 like mine and his hasn't given any indication of being iffy. In the meantime, follow some good habits:

1) Always start the bike in neutral with the clutch pulled in.
2) If the clutch tends to stick in the cold or after the bike hasn't been used for a while - rock the bike to unjam the plates before starting
2) If you find you're having to crank the bike a lot to get it started, get it tuned/fixed.

That'll keep the pressure off the sprag.

If you are cranking the starter and you hear a vicious sounding CLACK, and the cranking hesitates, that's the sprag slipping. Mine went from occasional to all the time in about 5 or 6 months. Then I fixed it myself (as did Stan) and it wasn't as bad as I feared.

The pannier brackets came with mine. Keep an eye on ebay, they might come up there and use keyword searches in this forum - I think some folks have made their own or adapted others. Good luck.