Broken Flex Plate

[justinburnett]

Got my truck a couple of weeks ago, and of course, about the time I got it home one of the teeth on the flex plate broke off (among other problems I found on the way home)! I knew it would need replaced but I thought maybe I could limp it for a bit while I saved some money to have it replaced. Now it sounds like I lost a piece of the next tooth too. Looks like it needs done ASAP. Problem is I've never dropped an auto trans before, and never anything on a 4x4, so I'm kinda clueless about how to go about it. I can't afford to pay to have it done, so I was wondering if someone here has done it and could point me to some good instructions, or at least let me know the hard bits that I should be ready for or the general outline.

Someone told me you can do this without actually removing the transmission but I don't know if that's really plausible.

Also, where would I get a good deal on a new or slightly pre-owned flex plate?

Thanks for the help!

[y5mgisi]

they are pretty cheap at the parts houses. About $30 or so. You pretty much have to pull the motor or trans to get it off. you "could" do it by just removing all the bell housing bolts and the trans crossmember bolts and "slide" the trans back about 3-4".

[silvereagle07]

When you do install the new flexplate,be sure to torque the bolts. The flexplate could break around the bolts if you don't. I've done it.

[68 TT]

It is definitely easier to pull the engine rather than dropping the trans & transfer case.

It will give you a chance to clean it up, put in some new gaskets, a timing set and a fresh coat of paint too while you have easy access to it all.

Might as well degrease the engine compartment too.

[babyJay]

I'm with Y5, don't settle for a used plate when they're fairly cheap at the chain stores, it's not worth having to pull it apart again when a tooth breaks off of the new "used" one. I have a few laying around in my garage but the chances of me ever using one is slim.

I wouldn't try doing it with the trans in place, seems like you'd be making more work for yourself trying to get out of work. Chances are the flexplate bolts are going to be no fun with wrench, and you may need an impact with a good 6 sided socket.

You'll have to rent or borrow a good transmission jack to pull the trans/transfer case together. Like Y5 said, you may not have to completely remove it, just slide it back.

Don't be afraid of it, just jump in there do it. This is how we all learned our "first" time around. Don't forget to have a buddy under there with you, don't try to pull this off by yourself, you will get hurt. Good luck.

[babyJay]

...and don't forget to put a few drops of locktite thread locker on th the FP bolts with you put the new one on. Like silvereagle says, use a torque wrench and torque them to spec.

[justinburnett]

If the new plate's that inexpensive I'd definitely go new rather than used. You're right, another 30+ year old plate is probably going to be ready to break too.

I like the idea of just pulling the engine... only problem is I've never done that either. I pulled a manual trans off a passenger car once to change the throwout bearing... that's about it. Have neither engine lift nor transmission jack, so I'll have to rent one or something either way. I liked the idea of just sliding the trans back a few inches to get in there and undo the bolts, but if they're torqued on there pretty well, and should be, plus sitting for probably 38 years... they probably will be a **** to get off.

I have no shop/garage to do this so it'll be in the driveway so I can't do a rebuild right now. Maybe another time, but I pretty much need it in and out in a day if I'm pulling the whole engine. It seems stupid, but I can't find a book for my truck in any shops out here. They have everything else, but either they're all sold out, or just don't have carry GM books, and I don't really have a lot of places to choose from. One of the times I wish I lived in the city.

Anyway, I'll try to poke around the internet and see if I can find info on pulling the engine and then go down and see where I can rent a hoist. Do I have to remove the transmission mounts too or will the engine just slide forward and out? It's going to be an adventure for sure. I'll post my failure on here if I live through it.

[Buick455]

I had a cracked flex plate on my 92 K1500 and it would blow oil from the transmission seal under load. We had to pull the trans to find the problem.
The biggest problem with pulling the trans is getting the exhaust out of the way but either way you have to disconnect it from the manifolds. I guess I would pull the engine too.

[motornut]

in my case the flywheel was 32 years old ,rotated the converter to see the flatter spots and yes ,went for a new flywheel.had to pull the block tho seemed easier to me then tranny.your gona need a spot for a week, dry and flat.blocks for the wheels,floor jack,and engine lift ,chains.make sure the block has lifting tabs on it ........

[68 TT]

Originally Posted by babyJay

...Don't be afraid of it, just jump in there do it. This is how we all learned our "first" time around. Don't forget to have a buddy under there with you, don't try to pull this off by yourself, you will get hurt. Good luck.

I agree. This is a great opportunity to learn and get to know your truck.

Find a friend or family member that has some experience that can be there with you and guide you along. It is not that hard to do.

Take a bunch of pictures before you take anything apart and as you go use some tape and a permanent marker to label everything to help you remember where it all goes.

It is much harder to muscle a trans & transfer case up into place and get everything aligned even with a friend and a transmission jack than it is to drop an engine in by yourself with an engine crane. I have done this job many times by myself both ways and it is by far easier to pull the engine.

With an auto trans it shouldn't take you more than a few hours to get the engine out even taking your time not knowing what to do. With a little guidance you can easily get this whole job done in a weekend.

Either way you go, pulling the engine or trans & transfer case, take your time and be safe.

[justinburnett]

Okay guys... I've got 24 hours. This is probably going to be a disaster, but I'm going to do it. Have to rent a engine hoist at $40 a day, so.... Going to drive down to pick it up at 2. Come home, put the hoist in the back, start stripping the engine of anything that's in the way, then to the parts store (don't know what exhaust gaskets I need cause they said there were 3 listed for that engine depending on the heads) and get a manifold gasket set, and the plate. Tomorrow morning, I yank the engine, put the new plate on, and put it back down so I can get the hoist back a little after noon. Then come back and start bolting stuff back together and pray that it starts.

So... in about 30 hours I'll let you know how it went and you can all laugh at me!

Actually I need to get it running by 2 tomorrow cause I don't have anything else to put the hoist in to take back. Crap. Oh well, still, I can do it.

To pull engine, I need to take out radiator, pull all wires, unbolt exhaust manifolds, unbolt bell housing bolts, remove starter, disconnect torque converter, disconnect choke and throttle cables, remove power steering pump, pull vacuum lines, transmission cooler lines.... anything else I need to plan on? I'm pretty sure I can do all that, I've just never done it all at once. Do I need any special tools for any of this? Am I going to want to kill myself before I get this done? Any little tips will be appreciated.

I've never really failed at trying to fix a car if I knew what was wrong (there were some computer/sensor issues I never figured out), So I might as well just do it. I can afford $100 for this project but that's about it, and that's what it's going to cost when it's done (if I don't run into anything breaking, otherwise I'm ****ed), the place I called for a quote said no one would do it for under $500. Might be true, might not, but I want to drive the thing, not let it sit and rust away.

Oh, and speaking of rust, I had some questions about rust converters and stuff before, but it's kinda gone on the back burner now since it won't hardly start now.

Thank you everyone for your help with this!

[Slonaker]

There's a coupon here for a cheap engine hoist at Harbor Freight for $100. You can probably buy this hoist as cheap as you can rent one. There's also a 20% off coupon and one for an engine stand that might come in handy.

It is just a cheap hoist, but it should be good enough to pull a small block Chevy. This is assuming it will lift high enough to clear a 4WD. I wouldn't know, but I'm sure someone in the thread does.

http://www.harborfreight.com/magurl1

BTW, that's a nice closeup photo, motornut!

Slonaker

[babyJay]

Originally Posted by Slonaker

It is just a cheap hoist, but it should be good enough to pull a small block Chevy. This is assuming it will lift high enough to clear a 4WD. I wouldn't know, but I'm sure someone in the thread does.

That's all I have is a HF model. Been using it 6 years with no problems whatsoever. It's probably had at least 20 or more pulls/dropins done with it. You can circumvent the height limitation by letting the air out of the front tires of the truck if you need to. If all you're doing is disconnecting it, raising it, and pulling it forward (not completely removing from engine bay), you won't have any problems at all.

Tips:
Grab yourself lots of drain pans, buckets, or whatever you need to catch the coolant and transmission fluid.

I like to remove the distributor cap and rotor to prevent damage/breakage from bumping the firewall.

When you go to bolt the block back to the trans, make sure the Torque converter is fully seated in the trans, and spins freely. DO NOT use the transmission bolts to "pull" the trans and engine back together. Take your time and make sure the trans is fully on the guide pins and there is a gap between the flexplate and converter. This is very important, as it can trash the inside of the trans if not done properly.

Get yourself some mosquito spray

Pen up the dog so you don't have to worry about him running off

Take plenty of pics as stated before, and don't forget to share them here in the thread.

Good luck, and be safe.

[Buick455]

I second the HF hoist although that is not what I have it works and better than renting one. Buy an engine stand while your there. Print off a couple 20% coupons before you leave.

[justinburnett]

I would head to harbor freight right now, but it's a 200 mile trip to the nearest one, and like I said, I need to pull this whole job under $100 dollars or I'm covering the overrun out of rent. Work's been spotty lately. Last thing I needed was something to go wrong right now, so of course it did. Even if i did have some spare change around to make up the difference, I still wouldn't feel comfortable driving it anywhere right now. You have to manually turn the engine past the broken teeth, and then try and start it and hope it fires before it goes one revolution cause it'll hang up again in the dead spot, or lose traction, rebound backwards, catch on the back teeth with this horrible grinding clank, and then maybe skip the gap and keep turning. It hurts me to hear the poor thing! Gonna drive it (try to anyway) one more time like this down to pick up the hoist (leave it running) and then drive it back home and start ripping it apart.

I really wish I could buy that hoist cause I'm going to need it again in a couple weeks to put a new engine in my "commuter" car that's taken me almost a year and $1,200 (didn't know it was going to cost so much) to finish. It's just not done yet, so I'm stuck right in the middle of two projects with nothing to drive but a motorcycle, which I like much, but it sucks in the rain/snow/cold that's on its way out here soon. Should be in the teens at night in a couple of weeks. I'll take some pictures and video in case I get confused in the re-assembly, and I'll get a link to that stuff in here when I can so if someone else needs it maybe it'll help them in the future.

[68 TT]

Originally Posted by justinburnett

Okay guys... I've got 24 hours. This is probably going to be a disaster, but I'm going to do it. Have to rent a engine hoist at $40 a day, so.... Going to drive down to pick it up at 2. Come home, put the hoist in the back, start stripping the engine of anything that's in the way, then to the parts store (don't know what exhaust gaskets I need cause they said there were 3 listed for that engine depending on the heads) and get a manifold gasket set, and the plate. Tomorrow morning, I yank the engine, put the new plate on, and put it back down so I can get the hoist back a little after noon. Then come back and start bolting stuff back together and pray that it starts.

So... in about 30 hours I'll let you know how it went and you can all laugh at me!

Actually I need to get it running by 2 tomorrow cause I don't have anything else to put the hoist in to take back. Crap. Oh well, still, I can do it.

To pull engine, I need to take out radiator, pull all wires, unbolt exhaust manifolds, unbolt bell housing bolts, remove starter, disconnect torque converter, disconnect choke and throttle cables, remove power steering pump, pull vacuum lines, transmission cooler lines.... anything else I need to plan on? I'm pretty sure I can do all that, I've just never done it all at once. Do I need any special tools for any of this? Am I going to want to kill myself before I get this done? Any little tips will be appreciated.

x3 on buying the hoist. I have been using one for 12 years with no problems other than the paint faded from UV exposure. If you end up needing to rent the hoist for more than a day you have nearly paid for it already. All the rental hoists I have seen and used were complete garbage and sucked to use. If you are really tight on funds just take it back and tell HF it doesn't reach high enough to get the engine out of your truck so you want your money back. They will take it back most of the time.

You don't need to pull the exhaust manifolds, just disconnect the exhaust pipes from them. Depending upon the design of your manifolds you may not have any doughnut gaskets to deal with. My 78 did not have them. Many times they are reusable if you have them.

You will need to pull the starter to get the engine clear of the crossmember. Make sure you disconnect the battery first.

Definitely pull the radiator to keep from damaging it with the engine. You will need to pull the fan off to get the fan shroud out so the radiator can come out.

You only need to disconnect the power steering hoses from the gear box. This way the whole accessory system can stay on the engine intact and save you some time. You just need to disconnect the hoses and wires from the accessories. Plug the fuel supply line with a spare 3/8" bolt and clamp it in place to keep the fuel from spilling everywhere.

As stated earlier definitely pull the distributor cap and rotor off to prevent damaging them. Once it and the starter are out of the way getting to the bell housing bolts is much easier.

Drain your oil and pull the filter as you will most likely damage the filter getting the engine out or putting it back in plus you can use the extra clearance to make things go together & come out easier.

Don't forget to block up the transmission as it will droop once it disengages from the dowel pins on the back of the engine.

[motornut]

WORK SLOW
Mark the distributer postion.i didn't have to remove the cap or rotor but i did have to turn the dist to put a second lift tab on the second bolt in, from the back, pass side.
Very important to open the legs,spread out the weight,move very slow out,no sudden moves,and lower it as soon as it's out.safer to push it low to the ground then up high,i use the bar in the end of the legs to lift it a bit to get over a bump or ridge ......and be sure to torque it back together
A slight list....
9/16, 5/8, 11/16 wrenchs +sockets + swivel
long/lots extentions to lay on your back under and reach up to the housing bolts if you can't get them from the top
unhook wire harness at firewall 3/8ths wrap up to the block
my truck i was able to angle jack the two (engine/trans)up almost to touch the body,mount bolts were out,then block the tranny with the floor jack,and lower the engine and they should/could come apart
go SLOW

[justinburnett]

I totally agree about the engine hoist. I hadn't thought of using it and taking it back. Either way though, I really can't get out anywhere to get one. Went one place earlier and asked about buying one but they said $550! Rented one for $30 for the next day and a half and I'm just going to have to make do with that. I like the idea of taking the exhaust pipes off at the manifold, that'll save some time and a little money. Probably be easier too, but my problem then is: where do I connect chains to lift the engine? I was going to use the exhaust manifold bolts but if I leave them in, is there somewhere else I can bolt to safer or easier? remember I've never done this before so if that's a stupid question, sorry, but I don't know any better. Thanks for the tip on blocking up the trans, wouldn't have thought of that. I think I'm ready to go. Got it started (after much frustration) and on it's last drive, so now I'm just waiting for it to cool so I don't burn myself too much, and then it's time to go to town with the wrenches.

[justinburnett]

I'm in a hurry, but I'll be slow about the actual engine movement for sure, and the labeling of wires. Thanks. One thing I do need, if someone could look them up for me, is torque specs for:

Bell bolts
torque converter bolts
flex plate bolts
motor mount bolts
exhaust manifold bolts (in case I end up having to use those)
Anything else you guys might think I need by way of specs.

You're awesome! Hope someday I can help people out too.

[68 TT]

Originally Posted by justinburnett

I'm in a hurry, but I'll be slow about the actual engine movement for sure, and the labeling of wires. Thanks. One thing I do need, if someone could look them up for me, is torque specs for:

Bell bolts
torque converter bolts
flex plate bolts
motor mount bolts
exhaust manifold bolts (in case I end up having to use those)
Anything else you guys might think I need by way of specs.

You're awesome! Hope someday I can help people out too.

35 ft-lbs for the bell housing, torque converter, exhaust manifolds & motor mount bolts.

85 ft-lbs for the flex plate bolts with some locktite on them too. You can stick a large phillips screw driver through one of the converter mount bolt holes on the flex plate and turn it against the block to stop the rotation so you can torque the flex plate bolts in place.

[justinburnett]

Sounds good to me. Thank you very much. I think I have locktite floating around somewhere. Easy to remember too.

[motornut]

stock blocks should have lift tabs @intake bolts,last one to back of truck at pass side,opposite on drivers, first on the front,i hook the open hook "in" if poss.

(Before lifting)make sure to tie off the converter,rope or wire threw the housing bolts across between the flywheel and torque to keep the converter with the tranny(make this tie tight) you don't want it coming off,very messy

[justinburnett]

I wouldn't have thought about the converter falling off. Thanks.

I think I got all the stuff disconnected on the bottom end, besides the engine mounts. Loosened them up but didn't remove the bolts yet. Got the exhaust flange nuts off but I can't seem to get the pipes to come free. there's a little play there... hoping when I pull up on the engine a little it'll loosen them farther. Still have to pull the radiator, PS pump hoses, a few wires, and the top bell housing bolts, and I think it's ready to start lifting. Going to get started in about an hour. It's really cold. Glad this didn't happen in December or something.

I started taking pictures before I got going, but then I was so greasy I didn't want to touch my camera. Didn't think about that... so I was wrong when I said I'd have pics of the process. Kinda disappointed about that, but I don't want to ruin the camera.

[justinburnett]

How many bellhousing bolts am I looking for, just so I know? Also, there were only 3 bolts connecting the flexplate to the torque converter. Is this right? That seems awful wimpy... How does it keep from shearing the bolts if you get on it going up hill with a load? Maybe I'm not understanding the relationship here, but isn't that the only thing that connects to the transmission to transfer power? I guess if it's 3, then it's 3 and it worked fine for the last 38 years so it must be good, but it still seems weird.

Still can't beat the pipes off. been wiggling and wacking at them with a rubber mallet, and they're free, but the keeper plate thingy won't slide over the studs. Should I bend them? I'm afraid to do anything that will keep them from bolting them back on, but now that I have the nuts off I sure don't want to pull the manifold anymore.

I'll check back later. Thanks again for everyone's answers and advice!

[babyJay]

Some Heavier duty transmissions have 4, but most are only 3. All the Torque Conv is doing is pumping fluid. There's not really any internal stress on those bolts.