Is It Really That Critical...Bellhousing Alignment...Experts...????

Viet Nam Vett · 10-19-04, 09:17 PM

Been reading a lot on the Centerforce Web page about how critical itis to make sure your bellhousing is plum to the tranny face as well as to the centerline of the Crankshaft.

Also ..I know that Keisler's warranty requires you to make sure yor Bellhousing is plum as per the above.

This all makes sence to me and I don't doubt what they say. You don't want to mess up the tranny input shaft or throw out bearing as well as the clutch assembly.

What is said here is that due to the quality of the Manufacturing of the bellhousings as well as the rear of the block castings Back in the day..there are inaccuracies in the tolerances.

But what gets me is ..if this is true...which it probably is...How in the heck did all those SB & BB cars come off the Generals line and last all these years with out tareing up input shafts and Clutch parts??

The General must have allowed somewhere for this discrepancy or they just didn't care.

Maybe John Z or SWC Duke would like to take a shot at this one. I have never seen a post in regards to this topic. Seems to me with all of the swaps going on out their as well as new clutches going in ...how many of you addrerss this item ...and how many have just disregaurded doing it or weren't aware of this..???

Seems like an important item to address....... :cheers:

Ken · 10-19-04, 09:21 PM

I know all of the manufacturers/suppliers such as Richmond, Kiesler, etc. specifically recommend using a dial indicator and stressing the importance of bellhosing alignment. I think this is due to the common practice of mixing and matching parts, especially aftermarket parts.

The parts as the leave the original manufacturer, were designed for each other and the tolerances are closely monitored.

My guess.

Viet Nam Vett · 10-19-04, 09:29 PM

Quote:

Originally Posted by Ken

I know all of the manufacturers/suppliers such as Richmond, Kiesler, etc. specifically recommend using a dial indicator and stressing the inportance of bellhosing alignment. I think this is due to the common practice of mixing and matching parts, especially aftermarket parts.

The parts as the leave the original manufacturer, were designed for each other and the tolerances are closely monitored.

My guess.

I here yah Ken...But...all those Bellhousings and block castings and trannys manufactured at different times thruout the midyear run couldn't have been as accurate as the tolerences spec-ed in 1000th's of an inch that the aftermarket croud today wants. You know as well as I do that back in the sixties...it was sell sell sell....Quailty???? Waht's That??

67HEAVEN · 10-19-04, 09:39 PM

Fuelie and I spent several hours going over things with a fine tooth comb. Considering the difficulty in doing it after the engine/tranny install, it's well worth doing before hand. We found enough mis-alignment that I'm glad we did.

Thanks Fuelie.

67HEAVEN · 10-19-04, 09:42 PM

Quote:

Originally Posted by Viet Nam Vett

Maybe JohnZ or SWC Duke would like to take a shot at this one.

I'm putting money on the table that John had a meeting with Zora on this very topic and can offer enough statistics on why it should be done to choke a very large Belgian horse.

Rowdy1 · 10-19-04, 09:43 PM

Last year when the T10 went in the 62 I replaced it with a Richmond Gear Super T10. When I built the engine originally, four years ago I scraped the stock aluminum bell and put a scattershield in because of the increase in HP. Everything went together the first time, new 11' Centerforce. When I put the Richmond in last fall, I couldn't get the trans in no matter what I tried. I ended up removing the stock dowel pins and inserting new ones off center to align everything properly. I replaced everything with the trans, pilot, refaced flywheel, clutch, pressure plate crossmember mounts everything. I was told the scattershield is not quality stamped and that it's not uncommon. This may not have been what you were looking for, my point being, take the time to dial it in, it beats pulling it back out prematurely for a bearing be it, pilot, mainshaft etc.

Viet Nam Vett · 10-19-04, 10:04 PM

Quote:

Originally Posted by Rowdy1

Last year when the T10 went in the 62 I replaced it with a Richmond Gear Super T10. When I built the engine originally, four years ago I scraped the stock aluminum bell and put a scattershield in because of the increase in HP. Everything went together the first time, new 11' Centerforce. When I put the Richmond in last fall, I couldn't get the trans in no matter what I tried. I ended up removing the stock dowel pins and inserting new ones off center to align everything properly. I replaced everything with the trans, pilot, refaced flywheel, clutch, pressure plate crossmember mounts everything. I was told the scattershield is not quality stamped and that it's not uncommon. This may not have been what you were looking for, my point being, take the time to dial it in, it beats pulling it back out prematurely for a bearing be it, pilot, mainshaft etc.

I hear yah Guys.....Oh....I do plan on Dialing it in just like my Keisler install.. and I'm useing the stock 621 Bellhousing on the 502. No large Belgian horse's for me.

I ain't gonna Flog my Rat has hard as the Heaven..!!!

I just can't figure the General spitting out all those drive line parts in all different sizes...

Randy Eads · 10-19-04, 11:31 PM

"But what gets me is ..if this is true...which it probably is...How in the heck did all those SB & BB cars come off the Generals line and last all these years with out tareing up input shafts and Clutch parts??"

I'm with you on this one Vet. The RPM and the horsepower were there in the sixties muscle cars no different (I think) compared to todays cars . 7-grand is 7-grand!. ..... seems like overkill!

I can see balancing and indexing the flywheel etc, but that practice has always been there.

Tom Bryant · 10-20-04, 04:49 AM

Another thing to consider when you are building a new engine is to have the bellhousing flange surfaced to a perfect 90 degrees to the crankshaft centerline. Then you can be sure it's square as well as centered.

Tom

Viet Nam Vett · 10-20-04, 10:49 AM

Quote:

Originally Posted by Tom Bryant

Another thing to consider when you are building a new engine is to have the bellhousing flange surfaced to a perfect 90 degrees to the crankshaft centerline. Then you can be sure it's square as well as centered.

Tom

Oh..Yeah....That'll be done for sure.... Don't want to mess around with 567 Lbs of Torque...

JohnZ · 10-20-04, 11:57 AM

Factory machining tolerances were pretty good, even in the 60's. I've always done a concentricity check when doing a clutch job on a car I didn't set up myself, and have never found a factory bellhousing out of spec; however, every Lakewood or McLeod I've installed has needed offset dowels to bring it into spec. Still have a drawer with three grades of Tavia offset dowels. Input shafts do NOT like to run off-center.

iron cross · 10-21-04, 11:46 PM

I have never heard of such problems with bellhousings. They only go in correctly. Dowel pins take care of that proceedure. I would imagine that most of the clutch problems result from a worn pilot or mainshaft bearing.

Tom Bryant · 10-22-04, 09:16 AM

As John said you rarely find a problem with a factory bellhousing. I have read a lot of builds in magazines where they have had to use offset dowels to center the transmission in the pilot bearing when using a stamped scattershield. You would think that in this day and age of high tech CNC machines that the aftermarket guys could get the mounting hole in the center. But then I read on the rod forums where a lot of those fancy CNC machined billet wheels aren't round either.

Tom