Looking for a Pilot Bearing 79 Trans Am

[TAKerry]

Sorry if this is in the wrong place, looking for the best exposure. I need a pilot bearing for my 79 Trans Am, Pontiac motor 400 ci. Got a clutch pack and wrong size bearing. Ordered what was supposed to be the correct one from NAPA, wrong size. Any good place to look for one of these?

[STEVE POLLARD]

Kerry - not sure if your on Facebook, but there is a group on there that might be able to help you out....

 

Steve

 

 

[Laughing Coyote]

Any numbers to go by?

[TAKerry]

Dont do fb. 

Best I could come up with if this makes any sense, the outside dia. is .9580 the inside diam. is .5940  

Thats of my digital caliper. Its hard to get the outside dia. reading as my calipers do not have very deep legs. I used a divider gauge set to the hole then measured that so I am sure its off a slight bit. Inside diameter is fine. Fits the tail shaft of the T-10 just fine. 

[Laughing Coyote]

http://www.gopherbearing.com/index.htm

Try these guys. 

[zepher]

This may sound silly, but did you check these guys?

https://www.rockauto.com/en/catalog/pontiac,1979,firebird,6.6l+400cid+v8,1250581,transmission-manual,clutch+pilot+bearing,1964

 

[1912Staver]

May sound silly but did you check a G.M. dealership parts counter ? Basic parts like pilot bearings are often available for a long time. It may fit other G.M. engines as well as your T.A.  Worth a try unless you already have.

[Ed Luddy]

With these Gen II Pontiac/Chevrolet  F body cars the transmission and clutch parts are a bit of a PTA to match. From what I was told the BOP and Chev  are different input shafts. Also some of the 400/403 Pontiac/ Olds dont work out so I'm told. I've found out the hard way. Got another coming up, 76 T/A with transplanted 350 SBC with a T-10 4 speed from unknown year as of yet. It also has a scatter shield and a few mod's for drag racing at the local track. We won't get into the 3rd member tonight.

[joe_padavano]

2 hours ago, Ed Luddy said:

With these Gen II Pontiac/Chevrolet  F body cars the transmission and clutch parts are a bit of a PTA to match. From what I was told the BOP and Chev  are different input shafts. Also some of the 400/403 Pontiac/ Olds dont work out so I'm told. I've found out the hard way. Got another coming up, 76 T/A with transplanted 350 SBC with a T-10 4 speed from unknown year as of yet. It also has a scatter shield and a few mod's for drag racing at the local track. We won't get into the 3rd member tonight.

All GM transmissions used behind V8 engines use the same input shaft. Pontiac engines use a pilot bearing with a 1.375" OD. Are these the original engine and trans in this car? Pontiac sometimes did not drill the crank for a pilot bearing if the engine was bolted to an automatic. If this crank has been drilled, it might not be the OEM size hole.

 

Butler is a good source for Pontiac parts:

https://butlerperformance.com/search.html?q=pilot+bearing

[Dave Mellor NJ]

Probably no help to you but they just had a 79 Trans Am in the current issue of Antique Automobile

[Frank DuVal]

6 hours ago, TAKerry said:

Fits the tail shaft of the T-10 just fine. 

Um, you mean input shaft? The tail shaft goes into the driveshaft front yoke.

[JACK M]

12 hours ago, joe_padavano said:

sometimes did not drill the crank for a pilot bearing if the engine was bolted to an automatic.

Mopar did this too. I made a pilot bushing to fit once when doing an engine swap. I was quite proud of myself with very limited experience with a lathe.

[pkhammer]

If the inside diameter is good and the outside diameter is too big, have a local machine shop turn the bushing to the correct outside diameter.

[TAKerry]

13 hours ago, joe_padavano said:

All GM transmissions used behind V8 engines use the same input shaft. Pontiac engines use a pilot bearing with a 1.375" OD. Are these the original engine and trans in this car? Pontiac sometimes did not drill the crank for a pilot bearing if the engine was bolted to an automatic. If this crank has been drilled, it might not be the OEM size hole.

 

Butler is a good source for Pontiac parts:

https://butlerperformance.com/search.html?q=pilot+bearing

Thought I responded to this, but maybe forgot to hit reply? Motor and trans are original to the car.  My builder that knows far more about Pontiac motors than myself said that there are a couple of different sizes for the pilot bearings, and that it can get confusing at times. Did not think about Butler, if all else fails will give them a call. My buddy that is building basically the same motor said he got his from Ames, so I will give them a shout first. Really was hoping that this would be a order parts, put together, get the engine mounted in the car. Not so. This thing has been fighting me for 5 years now! Sometimes I think it would be easier doing a brass era car with no parts available. At least you know going into it that everything has to be made one off. Ordering parts that are supposed to 'fit' and then they dont is equally frustrating.

[pkhammer]

@TAKerry I just did a quick search on ebay for "1977 Pontiac Trans Am Pilot Bushing" and had 85 results, mostly NOS Dorman branded bushings. Some only list part number but some list ID and OD as well. This listing for example has a .593" ID and a 1.09" OD. Dorman p/n 14650.

https://www.ebay.com/itm/195903212301?fits=Submodel%3ATrans+Am|Year%3A1977|Make%3APontiac&epid=169361485&hash=item2d9cbdcb0d:g:z8kAAOSwyV5isiqd&amdata=enc%3AAQAIAAAA8DLZx4kfLVnCRkJOMUO%2BQ2wdY%2FOND4A6OkOujq3MQnXpAXBnWYVCqn6OQjaJ1DmhhRwr2xT0pyAHbHJYJvL0E1vGdtW53qnUqmUCAWl1jgzMb%2By1tzDAvefOVjLAABvV3aEaBVRIB%2BDpaRukrqVgmK6Iy02GgNklsDmqcx8fO2AJ9MCEehaz12QMEpnEYmueQYwK7yIjb%2BWFjqIG8PebsSpp3CyRXAr4QWuqJX4Xs85uwB155BwegqKLCFO378zNfZ6hYHREo5p85e0yIsZbyixrZxSPV1chFldlcWJPwN1ekdtjSnQjLCk34Z1wZhkHkQ%3D%3D|tkp%3ABFBMpP6aycli

[joe_padavano]

1 hour ago, pkhammer said:

@TAKerry I just did a quick search on ebay for "1977 Pontiac Trans Am Pilot Bushing" and had 85 results, mostly NOS Dorman branded bushings. Some only list part number but some list ID and OD as well. This listing for example has a .593" ID and a 1.09" OD. Dorman p/n 14650.

https://www.ebay.com/itm/195903212301?fits=Submodel%3ATrans+Am|Year%3A1977|Make%3APontiac&epid=169361485&hash=item2d9cbdcb0d:g:z8kAAOSwyV5isiqd&amdata=enc%3AAQAIAAAA8DLZx4kfLVnCRkJOMUO%2BQ2wdY%2FOND4A6OkOujq3MQnXpAXBnWYVCqn6OQjaJ1DmhhRwr2xT0pyAHbHJYJvL0E1vGdtW53qnUqmUCAWl1jgzMb%2By1tzDAvefOVjLAABvV3aEaBVRIB%2BDpaRukrqVgmK6Iy02GgNklsDmqcx8fO2AJ9MCEehaz12QMEpnEYmueQYwK7yIjb%2BWFjqIG8PebsSpp3CyRXAr4QWuqJX4Xs85uwB155BwegqKLCFO378zNfZ6hYHREo5p85e0yIsZbyixrZxSPV1chFldlcWJPwN1ekdtjSnQjLCk34Z1wZhkHkQ%3D%3D|tkp%3ABFBMpP6aycli

The fact that the bushing in your link is show to be applicable to vehicles with Chevy motors should be a clue that it isn't correct for a Pontiac motor. Many, MANY aftermarket parts vendors list their Chevy parts as fitting every GM vehicle ever made because, well, don't they all have Chevy motors now? 🙄

 

[TAKerry]

I have been searching for the last couple of hours. I think I know more about bearing/bushing sizes now about as much as anything else.

I am beginning to think Joe P may be on to something as far as the crank being drilled. I have found one dorman bushing size that is really

close to what I think I need. When I clicked where to buy they gave me the list of all the local spots, auto zone, parts plus, etc. etc. So, I will go on a scavenger hunt tomorrow and see what I can come up with. All of the 'standard' sizes I am getting show 1.375 (Joe P). The bearing I found that is close is listed as Pontiac 1981?

When I got the car the motor was completely disassembled, the block and the transmission are both correctly coded to match the car perfectly, I was told all of the loose parts came out of the motor. When I sent to the rebuilder there was nothing mentioned about the crank not being correct? Motor has been run and although I have not heard it, was told it sounds great and will be strong runner.  If the bushing I am looking for does not pan out I suppose I will have to look for a machine shop to make the oversized one I have fit. 

 

I really wanted to get the trans installed and the motor put in the car over the long weekend, but doesnt look too good right now.

[pkhammer]

4 hours ago, joe_padavano said:

The fact that the bushing in your link is show to be applicable to vehicles with Chevy motors should be a clue that it isn't correct for a Pontiac motor. Many, MANY aftermarket parts vendors list their Chevy parts as fitting every GM vehicle ever made because, well, don't they all have Chevy motors now? 🙄

I wasn't suggesting that a part be purchased on ebay just because it says it fits. It is possible however that one of the listings may be correct and could be confirmed if the size or part number needed is known.

[Frank DuVal]

So the first question is are you looking for a pilot bearing or a pilot bushing? 

 

A Timken 7109 ball bearing is a National 7109 with dimensions, note the bearings are designed as metric (common):

 

Bore (Inch)	0.591
Bore (MM)	15.000
Design	Single Row Angular Contact
Inner Race Bore (Inch)	0.591
Inner Race Bore (MM)	15.000
Inner Race Radius (Inch)	0.025
Inner Race Width (Inch)	0.354
Inner Race Width (MM)	9.000
Outer Race Outside Diameter (Inch)	1.378
Outer Race Outside Diameter (MM)	35.000

 

Note I got these dimensions by studying the Rockauto list! There is a bushing listed, out of stock, with these dimensions:

 

Bearing Inside Diameter (IN)	1.175
Bearing Inside Diameter (MM)	15.011
Bearing Outside Diameter (IN)	1.382
Bearing Outside Diameter (MM)	35.103
Length (IN)	0.362
Length (MM)	9.195

 

These dimensions do not agree with the picture of said bushing.

 

Butler also lists the 7109 as fitting, as fitting BOP series engines (I guessed at the BOP in the product P/N) but also has a specific bearing for 455 engines and one for 389 engines, but yours is a 400, so again they just show the 7109 bearing.

 

To look at Butler and Rockauto I just clicked the links supplied above.

 

I have not looked at Ames.

 

Do the dimensions of the 7109 not fit your crankshaft? Have you received a 7109 bearing already, or just bushings?

[George Cole]

Hey Kerry,

 

How about calling one of AACA's prime sponsors, NPD Parts?

 

Regards,

George

[John348]

On 8/30/2023 at 11:26 PM, joe_padavano said:

All GM transmissions used behind V8 engines use the same input shaft. Pontiac engines use a pilot bearing with a 1.375" OD. Are these the original engine and trans in this car? Pontiac sometimes did not drill the crank for a pilot bearing if the engine was bolted to an automatic. If this crank has been drilled, it might not be the OEM size hole.

 

Butler is a good source for Pontiac parts:

https://butlerperformance.com/search.html?q=pilot+bearing

Good call Joe! GM did this with the Chevrolet crankshafts, the Turboglide transmissions required a different drilling to accept the centering of the torque converter and there is a special pilot bushing to adapt those crank shafts to be used with a clutch. I encountered this once and it was a real ah s!@t moment, but I recall I located the bushing and it was part of the HELP parts line, and it was on the rack at a PEP Boys. All of this was done pre-internet Any speed shops near you? Try calling some of the guys who advertise that rebuild four speeds they had to know somebody who encountered your problem and might know of a direction to point you. There is a guy on Long Island who rebuilds four speeds for years, ships them all over the country Larry Fisher, D&L Transmission (631)351-4837 he pointed me in the right direction with a similar situation a few times.

You have the measurements, you can always have one made with correct material! 

I would check the Pontiac parts books to see if there are different cranks offered for different applications, that might answer all the questions, then maybe check to see if GM offered different pilot bushings (I doubt they did)  

Edited September 1, 2023 by John348 (see edit history)

[TAKerry]

Local auto zone had the bushing I was looking for. Its measurements were diff. that what I came up with, I just figured I had error'd in my reading the caliper. It was too small on the o.d. by a long shot. So back to zero. I have resigned myself to finding a machinist to make one. So now the task is locating a machinist. I am sure there is someone local to me, I would imagine for someone qualified it would be rather simple. I hate to think that this will be put on the back burner and no one will have the urgency that I have. Motor has been at the builders for 3 years now, finally got and ready to install. Being held up by a $20 part now! I really wish the machinist that worked on the motor would have had enough sense/knowledge to check to see if the standard pilot bearing would have worked before he put everything together!!!

 

[John348]

If they are so hard to find maybe have more then one made? Maybe on one of the specific forums announce that you are going to have a special run made and you are taking orders? Just a thought, maybe a way to get yours paid for and have a spare on the shelf. 

I would suggest replacing the front bearing on the tranny as well, excessive play can contribute to premature wear of the bushing.

[Pfeil]

On 8/30/2023 at 2:33 PM, TAKerry said:

Sorry if this is in the wrong place, looking for the best exposure. I need a pilot bearing for my 79 Trans Am, Pontiac motor 400 ci. Got a clutch pack and wrong size bearing. Ordered what was supposed to be the correct one from NAPA, wrong size. Any good place to look for one of these?

Ames Performance Engineering

F28.pdf (amesperf.com)

[TAKerry]

Ames has the standard size that does not fit, along with all of the other vendors. I found one wholesaler in Cali that had what I believe to be the correct size but minimum order is 100! Probably wont ever need more than one, but will def. get a couple of them made. 

[joe_padavano]

Are you sure the OD is 0.9580? The normal Chevy pilot busing is 1.094" OD. The ID is 0.592", which is the same for all GM transmissions. If it's really 0.9580 OD, I'd just get an off-the-shelf Chevy bushing (they're like $6 each) and have your local automotive machine shop turn down the OD to fit. So long as concentricity is maintained, this isn't that critical - keep in mind that the pilot bushing is only in use when you have the clutch depressed. We've spent more time talking about this than it takes to do it, to be honest.

Edited September 2, 2023 by joe_padavano (see edit history)

[Bloo]

While trying to find an oddball pilot bushing several years ago, I discovered references to no less than three(!) possibilities for the crank hole size in small block Chevys, and I wasn't even looking at anything newer than 1970. By far the most common is the 1.094 @joe_padavano is talking about.

 

The bushing I was looking for then wouldn't help you, but if you haven't looked at Advance Adapters (by measurement) you should. They have a rather large collection of oddball pilot bushings.

 

[Frank DuVal]

I'm on vacation so I do not have one to measure, but call Clark's Corvair and see what the OD of their bushing is (P/N C701). The ID is the same as most GM transmissions, as I use an old input shaft from a GM transmission my father had from YEARS ago to drive them into Corvair cranks!

 

OK, no need to call, I found this:

 

https://corvaircenter.com/forum/viewtopic.php?t=904658

 

It is ~.904" OD

Edited September 3, 2023 by Frank DuVal (see edit history)

[1912Staver]

If you have one with the correct I.D. and slightly too large an O.D. you can always use a drill press and a file to carefully reduce the O.D. to what you need.  Just take your time and frequently measure until you get down to the size you need. A lathe is quicker and more accurate, but it is just a pilot bushing after all. I am assuming we are dealing with a bronze or similar bushing and not a bearing. 

[TAKerry]

7 minutes ago, 1912Staver said:

If you have one with the correct I.D. and slightly too large an O.D. you can always use a drill press and a file to carefully reduce the O.D. to what you need.  Just take your time and frequently measure until you get down to the size you need. A lathe is quicker and more accurate, but it is just a pilot bushing after all. I am assuming we are dealing with a bronze or similar bushing and not a bearing. 

Can you pm a bit of detail? I kinda thought with a soft metal it should not be too hard to size but to do it in a perfect circle was my worry. No lathe (at least metal, I have a wood lathe) but I do have a drill press.

[joe_padavano]

15 minutes ago, TAKerry said:

Can you pm a bit of detail? I kinda thought with a soft metal it should not be too hard to size but to do it in a perfect circle was my worry. No lathe (at least metal, I have a wood lathe) but I do have a drill press.

This is the problem. You need a pilot (holder) that exactly centers the bushing to keep it concentric. The drill press method is frankly kind of half-fast.

[1912Staver]

I agree that it is a less than ideal way around the problem. But if only a small amount of material needs to be removed it can, with care work. You do need to find a piece of round stock that is a close match to the I.D. of the bushing. Slightly larger is ok as long as it just ends up as a slight interferance fit. But slightly too small and things  won't work. Bushing will stop turning when file pressure is applied.

 I always hang on to small pieces of cold rolled round stock. I have a whole bin full of odd off cuts. You never know when one will be just the right thing for a job. It's also why it has taken 7 months and still counting to move my house and shop to the new place. So much  " stuff " accumulated over the last 45 years or so.  But only 3 lathes , none of which work at the moment. All are partially dismantled for moving. I am going to hire a small crane truck to move the things too big /heavy for my cherry picker and car trailer. Biggest lathe, milling machine , Lincoln Ranger welder etc.

Edited September 3, 2023 by 1912Staver (see edit history)

[Dave39MD]

I did have to use my drill press to take a little off a pilot bushing. I used a bolt through a rubber core the bushing went around. With a nut and washer I was able to tighten it so I could, as mentioned above, remove material with a file until it fit. It has been working fine for years but maybe I was lucky.

 

Dave

[TAKerry]

OK, heres my story and Im sticking to it. Apparently I was measuring the wrong spot inside of the crank. I put out quite a few feelers as well as heeded the info on this thread. I was able to get in touch with Scot at Butler performance. Great guy to deal with. He was more than helpful. I sent him a couple of pics and he informed me what I was doing wrong. He also confirmed that the bearing should be 1.377. Measuring in the correct spot I came up with 1.362. Figured a bit for my error. He also said it did look like a factory prepped crank which I took as a good thing as I thought that the numbers aligned with those of my car. New bearing ordered will keep you posted. In the meantime this $20 part has cost me, well I dont want to think too much about it. I ordered a set of inside reading calipers, they will be here on thursday (no longer need them but I will keep as I may need them at some point) $50. Ordered what I thought was going to be the correct bearing $10, + $15 shipping=$25, one bearing from autozone that wasnt even close, $5, 2 bearings that came with the clutch that were wrong and a $26 bearing that I was able to return to napa. 

Obviously I am not a mechanic but learning. I was thrown off from the beginning when the bushing that came in with the clutch pack was just a hair too big for the spot where I 'thought' it belonged. This was the tail wagging the dog at that point. It is way too small for where its supposed to be. 

Stayed tuned for more of my pain!, LOL

[Frank DuVal]

So it is the 7109 ball bearing? That only goes a short ways into the crankshaft due to the snap ring limiting depth?

 

Edited September 6, 2023 by Frank DuVal (see edit history)

[joe_padavano]

On 9/5/2023 at 2:43 PM, TAKerry said:

I was thrown off from the beginning when the bushing that came in with the clutch pack was just a hair too big for the spot where I 'thought' it belonged.

Unfortunately, the usual problem that parts vendors assume that all GMs are Chevies. I'll put money on the fact that the bearing in your kit is for a small block Chevy (the 1.094" OD noted above). I'll also put money that the clutch kit you got is listed for a Camaro in addition to a Firebird.

Edited September 6, 2023 by joe_padavano (see edit history)

[TAKerry]

57 minutes ago, joe_padavano said:

Unfortunately, the usual problem that parts vendors assume that all GMs are Chevies. I'll put money on the fact that the bearing in your kit is for a small block Chevy (the 1.094" OD noted above). I'll also put money that the clutch kit you got is listed for a Camaro in addition to a Firebird.

Exactly what Scott from Butler said!

[Bloo]

Bearing?!

 

If it was a bushing originally, I hope it's not a bearing. I realize you don't seem to have a lot of options, but if at all possible use a sintered bronze bushing, and make sure a magnet won't stick to it.

 

 

Edited September 7, 2023 by Bloo (see edit history)

[Frank DuVal]

Pontiacs in this year range with real Pontiac engines typically use bearings. Check the Rock Auto (I know, not always reliable, but it is what someone put into a computer database not that long ago) link way up above. Just a few years later with "corporate engines" they are back to bushings. Edit, the next year!

 

I do use the magnet trick on Corvair bushings, or should I say used to use, as now I buy them from a Corvair parts supplier and get the right bushing.

Edited September 7, 2023 by Frank DuVal (see edit history)

[TAKerry]

I asked Scott for his input on the matter, for those unaware Butler is the premier Pontiac engine builder in the country. He said either a bushing or a bearing would be fine. I had been on a search for a bushing but ended up buying the bearing. We shall see.