Biggus

iTrader: (1)

I`ve been building a couple of spare drives and was wondering if there was a rule of thumb for shimming the top bearing cup that is located between the upper and lower. What is a good place to start,and how about the shims for the front race on a left hand drive? and the front shims on a right hand drive? (lower)

Are the tolerances pretty wide from drive to drive, or are most TRS drives shimmed the same?

If you have to add shims, assemble, check backlash, dissasemble and try again, I can see how time consuming it can be to get them perfect!

Kurt.

Biggus

iTrader: (1)

TTT

Mbam

Kurt, the bearing between the upper and lower is shimmed with a depth mike. You want about .004 preload on it. There is a whole procedure for dong it. You really should have the factory manual to do those drives. Also the shim guages and an inch pound dial tyoe torque wrench.

Biggus

iTrader: (1)

Hi Marc, thanks for the reply. I have the shop manual and measuring tools, just was wondering if there was a good place to start with these drives other than adding and subtracting shims for most of the day. When checking for backlash in the lower do I need to install a new load ring each try during the shimming process?

I just did my left hand lower gearcase, I tightened the bearing carrier nut to achieve the 5 in lbs of preload on the bearings, everything seems fine but I have some in and out play on the propshaft. is this normal?

Thanks again for your reply

Kurt

Mbam

Kurt, endplay is not normal on a TRS. That means there is no preload on the prop shaft bearings. We do not use the load ring or o-ring while setting backlash, just tighten to preload spec and measure. Load ring is used upon final assembly.

.025 is always a good starting place, but better to start with the old shims.

Biggus

iTrader: (1)

Marc,

Thanks for the info. I really appreciate it! I`m one of those guys that does all his own work, It`s the only way I can afford to play with these toys.

Thanks again,

Kurt

KAAMA

iTrader: (1)

Biggus, Marc from BAM has good info and seems to always be willing to help. "Doctor Dave" is also another good source to ask about the TRS drives----he's done several of them and has them on his own 35' Cig with blower engines in it and makes them live. "Doug" has a 35' Cig and he runs a pair of naturally aspirated 540's, and had his drives rebuilt twice by two different shops and they broke each time within about 4-8 hours. He finally brought them to Dave and now has about 50 hours or so of running time on them---he's very happy and feels like he can go boating now without something breaking. You can call Dave and I think he'd be happy to help you out with reliable info. When it comes to shimming the drives he knows where the "sweet spot" is. I'm sure the info that Marc from BAM has given is good, but I just thought you might like a second opinion if you wanted it. Dave's number is: 269-944-0214 he lives in S.W. Michigan.

Biggus

iTrader: (1)

Well,

I`m glad we have such a wealth of information here!

I had assembled a spare left hand drive over the weekend and I was not comfortable with the end play in the propshaft. Marc at BAM hooked me up with the correct info. I did not have the bearing carrier tight enough to crush the thrust ring, therefore no preload on the propshaft bearings.

Marc, thank you very much for your information and taking the time to help out someone who you`ve never met.

Kurt