Replacing the flexplate without removing engine or transmission

[NJKelly]

Originally Posted by dmjlambert

Is this what the one I need looks like? I have the original style starter with diagonal mount holes, and 168 tooth flex plate.

Do you have a link for that bracket, I'm assuming you got from Amazon.

[dmjlambert]

I ordered it from eBay by searching for "Bracket 3965589". It should be for a 350 with 168 tooth flex plate and starter with diagonal mounting holes, if I believe the Internet.
http://www.ebay.com/itm/272011458486
I'll let you guys know how it goes when I try to install it.

[NJKelly]

Thanks

My son and I started on it yesterday, got all the bolts out in the bell housing with the middle one on the driver side the 4-inch bolt is too long it hits the body. All the other bolts we're no problem. So I'm going to try and put it in three and a half inch bolt in that spot and proceed according to your plan. With mine having the transfer case being a four-wheel drive I have to also figure that out. I'm thinking I might have to remove those brackets that hold it and at the same time support it along with the transmission to slide it back. If that doesn't work I'll probably end up having to drop the transmission do the job and then have the pain in the ass task of lining up the dowels when I reinstall it. Wish me luck.

[dmjlambert]

If you figure out a good way to get it done, post some pictures. abig84 had an interesting comment earlier about just needing a small amount of space opened up, just enough to get wrenches in there. The way I did it I had a luxurious amount of room, but that was probably overkill. You may be able to get by using abig84's method.

[NJKelly]

yeah I'm thinking I don't need all the space you had. I'm a pretty skinny guy with skinny forearms and skinny hands and skinny fingers, LOL and my son, 16 years old he's even skinnier still. I'll take a bunch of pictures and post them in this thread.

[NJKelly]

How many bolts are supposed to be holding the flexplate to the torque converter? I'm thinking somebody did a s***** job. I have them all out and there are only three. 1972 Chevy Blazer automatic transmission. Th350 with a 350 SBC.

[dmjlambert]

There are just 3 flexplate-to-torque-converter bolts on my 350 engine with TH400 transmission.

[Boog]

The long bolts deal to slide the trans back for clearance is a neat deal but me, I would take this opportunity to replace the front pump seal while it is apart. If it has been in there for a long time and is now disturbed it could go to leaking once you button it back up. This means the trans will most likely have to be lowered to remove the torque converter and replace the seal. It's cheap insurance.

[kazoocruiser]

Originally Posted by NJKelly

How many bolts are supposed to be holding the flexplate to the torque converter? I'm thinking somebody did a s***** job. I have them all out and there are only three. 1972 Chevy Blazer automatic transmission. Th350 with a 350 SBC.

I think if you look at your torque converter you will only see 3 places to run bolts into.

[BugzC10]

Originally Posted by NJKelly

How many bolts are supposed to be holding the flexplate to the torque converter? I'm thinking somebody did a s***** job. I have them all out and there are only three. 1972 Chevy Blazer automatic transmission. Th350 with a 350 SBC.

Five bolts holding the flexplate to the crank and three bolts hold the torque converter to the flexplate.

[NJKelly]

Thanks oh, I thought three was half as many as necessary. Glad to hear it was not a problem. I'll look into that front pump seal while I have it open, thanks.

[NJKelly]

Originally Posted by Boog

The long bolts deal to slide the trans back for clearance is a neat deal but me, I would take this opportunity to replace the front pump seal while it is apart. If it has been in there for a long time and is now disturbed it could go to leaking once you button it back up. This means the trans will most likely have to be lowered to remove the torque converter and replace the seal. It's cheap insurance.

so I have to drop the transmission and remove the torque converter to get at that am I right? I'm thinking that might have to happy anyway, the transmission being dropped as transfer case is proving to be a bit of a problem. Anybody else can chime in and tell me what else I should do while I'm there? I'd love to get as much accomplished as possible, $13 part here and $20 Part there while it's all opened up

[Boog]

Yes. The pump seal is behind the converter.

[kazoocruiser]

I dunno, maybe a rear main seal?

[NJKelly]

And by the way I did not buy the flywheel spinner. I simply put a wrench to each side of the flexplate to torque converter bolts and took them off. before I took off the second one I moved the flexplate to the position of the first one by doing it with only one wrench which then exposed the third one removed the second one, and moved to the other side of the transmission to get the third one, and it wasn't a problem. Hope that makes sense.

[NJKelly]

Originally Posted by kazoocruiser

I dunno, maybe a rear main seal?

I thought about that, I believe it's a two-part seal based on my research. I think I might, if it's not leaking, leave that alone. I definitely have a leak but as others have suggested it might be from the intake manifold it seems there's oil all on the back of the engine from that height on down. Lots of nuts and bolts are coming out easy because of the lubrication, LOL

[NJKelly]

So what are the other holes for? Not mine by the way.

[Boog]

If you are referring to the outward set of holes there are 6. If I'm not mistaken there are two patterns there. One set of holes fit a T350 converter and one set fit a T400 converter, I believe. It's been a while..

[3757chevy]

Originally Posted by Boog

If you are referring to the outward set of holes there are 6. If I'm not mistaken there are two patterns there. One set of holes fit a T350 converter and one set fit a T400 converter, I believe. It's been a while..

That is correct, they are a different diameter .

[rpmerf]

Originally Posted by NJKelly

... then have the pain in the ass task of lining up the dowels when I reinstall it. Wish me luck.

I take a bolt, cut the head off, grind it so it is a bit more pointy like a dowel, and cut a slot in it so you can install / remove with a screwdriver. Make 2. Put them in place of transmission bolts. Use them to line up the transmission. Once the transmission is in put a couple other bolts in, the pull out the studs and install bolts. It's a bit easier than the dowels alone as they are bigger and longer. Really helps when you have a manual transmission and need to line it up just right to get the pilot bearing in.

[NJKelly]

Originally Posted by dmjlambert

It is 2 wheel drive truck, no transfer case. I do suppose it would be different for a 4 wheel drive truck. In 1969 there was no additional support bracket for the starter on trucks. I would like to get one anyway before I do anything to the timing that could cause kickback.

I used your method and got the old flexplate out. I did not have as much room to work as you because the transmission jack I was using was hitting the crossmember. I moved it once to allow the transmission to move back further and probably could have moved it a second time to get even more room but didn't really need it. I think I mentioned earlier in another post the driver side second bolt had to be 3in as it hit the firewall. The four was too long. Other than that I disconnect the transfer case to frame mounts and took off the rear drive shaft as there is no leaking problem and took off the front drive shaft as it connects to the differential. Got in front of the truck and started kicking the Jack hitting the front and rear wheels at the same time with my feet and was able to move the transmission without any problem whatsoever. I came back to this post to double-check the correct direction of the flexplate. Lots of conflicting information out there. Hopefully tomorrow with rain in the forecast my son and I will get underneath it and install new one. Looking at your pictures of your old flexplate it looks decent, mine the teeth look like they were hit with a hammer.

[dmjlambert]

Originally Posted by NJKelly

...Looking at your pictures of your old flexplate it looks decent, mine the teeth look like they were hit with a hammer.

It looks like in my pictures I did not show the parts of the flex plate where the teeth were ground up. It was really messed up bad, but had some good sections with some good teeth left. I could start the truck if the engine happened to stop at a place with good teeth where the starter engaged.

[NJKelly]

Originally Posted by dmjlambert

It looks like in my pictures I did not show the parts of the flex plate where the teeth were ground up. It was really messed up bad, but had some good sections with some good teeth left. I could start the truck if the engine happened to stop at a place with good teeth where the starter engaged.

Same with mine. I don't recall did you mention changing the starter as well? When I was searching for a flexplate at advance Auto website they actually sell just the cog for the starter as opposed to replacing the entire starter. Have yet to inspect mine to see if that needs to be changed out, the guy at the auto parts store said it's probably not in bad shape despite the flexplate being bad because it's a bigger bulkier piece of metal. We'll see.

[dmjlambert]

My starter was OK. I had a saga going on at the time, and the Reader's Digest version is I thought (due to my improper diagnosis) I had a bad starter, and replaced it with Skip White's best mini starter, which promptly chewed up my flexplate. I then replaced the correct bad component on my truck, which was the positive battery cable, and put the original starter back on, and replaced the flexplate. The original starter works great. I am a lousy shimmer, but I have a shade tree mechanic friend who shimmed it for me.