Bellhousing alignment

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Paul Davidson

Paul Davidson

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Can someone tell me what the factory spec is for bellhousing alignment
 
I am not sure of your car and year, but for example: Per the 1970 Plymouth service manual, bellhousing bore runout relative to crankshaft should be within 0.008" total indicator reading. Meaning the bellhousing bore center should be within 0.004" of crankshaft center. The bellhousing face should be with 0.006" total indicator reading of the crank (and flywheel).
 
Most folks seem to miss checking the face's angle in relation to the crank/block. It does mater just as much as the bore run-out.
 
Bellhousing is bored with the engine block. That's why we should verify this when exchanging bells from one engine to another or aftermarket Bellhousings.
 
CRUZE 418 said:
Bellhousing is bored with the engine block. That's why we should verify this when exchanging bells from one engine to another or aftermarket Bellhousings.
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Not saying you're wrong, but I've never in my life seen or heard of this, and I'm wondering how that's supposed to work with a torquflite.

I'd have to red X this one
 
Well, think what you want, but I didn't pull this particular statement out of thin air.
 
jos51700 said:
Not saying you're wrong, but I've never in my life seen or heard of this, and I'm wondering how that's supposed to work with a torquflite.

I'd have to red X this one
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Somewhere I have a picture of the fixture being used at the factory. This is a well known fact. @Dan Brewer posted a pic on FB a while ago showing the fixture.

blockdept2.jpg
 
Jeremiah (jd) said:
Somewhere I have a picture of the fixture being used at the factory. This is a well known fact. @Dan Brewer posted a pic on FB a while ago showing the fixture.

View attachment 1716329935
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What’s sad is a couple of the worst bell housings I’ve indicated in were factory units that I know were OE to the car.

One was my 72 Demon. I wanted to buy a scatter shield but my dad didn’t want to because he said it would be way off.

When it came time to indicate the bell housing in, it was .080 out from about 4 to 11 o’clock. My dad thought I was BS’ing him because he knew I didn’t want it so he crawled under there and verified it.

So I ran down to the speed shop and bought a scatter shield. It was only out .020 so I sent it. I used that thing until about 2006 and I bought it in 1981.

I think two others I found were out like that. All OE and they all shifted fine, didn’t eat pilot bushings or break the bearing retainer.

My buddy had a Chevy Nova that was killing pilot bushings and it finally broke the bearing retainer.

He checked it and it was .100 out. You could shift it. It just ate pilot bushings about every 3-4 months.

I was stunned it was out that far and the gear box still went in.
 
Newbomb Turk said:
What’s sad is a couple of the worst bell housings I’ve indicated in were factory units that I know were OE to the car.

One was my 72 Demon. I wanted to buy a scatter shield but my dad didn’t want to because he said it would be way off.

When it came time to indicate the bell housing in, it was .080 out from about 4 to 11 o’clock. My dad thought I was BS’ing him because he knew I didn’t want it so he crawled under there and verified it.

So I ran down to the speed shop and bought a scatter shield. It was only out .020 so I sent it. I used that thing until about 2006 and I bought it in 1981.

I think two others I found were out like that. All OE and they all shifted fine, didn’t eat pilot bushings or break the bearing retainer.

My buddy had a Chevy Nova that was killing pilot bushings and it finally broke the bearing retainer.

He checked it and it was .100 out. You could shift it. It just ate pilot bushings about every 3-4 months.

I was stunned it was out that far and the gear box still went in.
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My worst one to date was a 74 400 mated to an early '66 10.5" factory bell. It was very close to maxing out the .021 offset dowels at .008 TIR. Hoping my new Browell is close!
 
I bought a pallet of new assembly line SB overdrive bellhousings years ago. The bore for the retainer was rough finished, leaving around 0.03" in the bore. I have had a couple Hemi bells over the years that were the same way.
 
Thank you for the information have two bells from lakewood one is .056 out and the other is .046 both need to go up but the starter is binding on the flywheel so going up isn't an option
 
Dan Brewer said:
The new aluminum Lakewood bell??
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Yes one of those I've spoken with you about my bell problems and and I'm also dealing with lakewood or holley actually and they sent me a new bell and it indicates in at zero at 12 o'clock and 46 at 6 o'clock so I'm waiting to hear back from them about what the next move is. In their defense they are working with me Ona part that I bought 3 years ago but has never been run just installed in
the car My original problem was the starter drive getting stuck in the flywheel and I've since gone down a rabbit hole with bell alignment and trying to get it straitened out I'm going to be calling brewers tomorrow to order a bell from them
 
jbc426 said:
Most folks seem to miss checking the face's angle in relation to the crank/block. It does mater just as much as the bore run-out.
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Yup. If folks would only listen to the "get a factory service manual" advice, it's all laid out in there.
 
Paul Davidson said:
Thank you for the information have two bells from lakewood one is .056 out and the other is .046 both need to go up but the starter is binding on the flywheel so going up isn't an option
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Dang, that's just pathetic.
 
The story that I heard is that yeah....the bell housings were bored to the finished size when new. Rick Ehrenberg wrote about this in Mopar Action magazine. We've often swapped 4 speeds into cars with automatics and never checked runout and been just fine.
Why? Well, the guys at SST told me that the 833s were more forgiving of excessive runout than the newer transmissions like the Tremec TKO and TKX. Oddly, I'm just now learning of the spec the factory called for and it isn't much different than with these Tremec transmissions.
 
Kern Dog said:
The story that I heard is that yeah....the bell housings were bored to the finished size when new. Rick Ehrenberg wrote about this in Mopar Action magazine. We've often swapped 4 speeds into cars with automatics and never checked runout and been just fine.
Why? Well, the guys at SST told me that the 833s were more forgiving of excessive runout than the newer transmissions like the Tremec TKO and TKX. Oddly, I'm just now learning of the spec the factory called for and it isn't much different than with these Tremec transmissions.
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I can believe that. I think all the older gear boxes are more forgiving in that respect.
 
I went with a QT in 2010. Bought the offset dowels, farted around for 2 days. Gave up and put the factory dowels in and threw it together. Used the factory dowels with my current engine and have had ZERO problems in either. And I do run the snot out of it regularly.

An old Mopar guru told me if the tranny installs easily, forget about it. The 833's are very forgiving. Basically, if it goes in, it'll be fine. :rofl:

Just my experience. Yours may differ
 
Ironmike said:
I went with a QT in 2010. Bought the offset dowels, farted around for 2 days. Gave up and put the factory dowels in and threw it together. Used the factory dowels with my current engine and have had ZERO problems in either. And I do run the snot out of it regularly.

An old Mopar guru told me if the tranny installs easily, forget about it. The 833's are very forgiving. Basically, if it goes in, it'll be fine. :rofl:

Just my experience. Yours may differ
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The real problem was that my starter was hanging up in the flywheel
 
Pontiacs used to have an interference, you would hear it when you let go of the key and the engine started. They had a spacer between the starter and the bell. Quiet from the factory, forget the spacer when changing out the starter and then you hear the noise.
 
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Yeah. QT kinda lacks precision as far as starter bolt up. I ended up just using the biggest bolts I could fit through the starter holes(no bushings), and that seems to work fine for me.

Did Mopar even use bushings from the factory?
 
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