Pulling Engine, Can't Remove Trans Bolts
Thread Starter
Junior Member

Joined: Apr 2025
Posts: 21
Likes: 3
Car: 1986 Trans Am
Engine: 350
Transmission: 700R4
Pulling Engine, Can't Remove Trans Bolts
I'm pulling the 305 out of my 86 TA, and I have everything removed except for the transmission bolts around the bellhousing. They seem to be incredibly tight, and even my impact hasn't been able to turn them. I tried hoisting the engine about 1/2" to relieve any tension that the motor may be putting on them, and even that didn't seem to help. I would like to avoid pulling the entire trans, as I don't have a shop or a lift and I've just got the car up on ramps. Does anyone have any tips on getting these bolts undone? Thanks so much!
Supreme Member




Joined: Oct 2000
Posts: 3,239
Likes: 809
From: Park City, UT
Car: '92 Corvette, '89 1/2-a-'Vette
Engine: LT1, L400
Transmission: ZF6, T5
Axle/Gears: 3.45, 3.31
Re: Pulling Engine, Can't Remove Trans Bolts
Breaker bar and some sweat equity. Your extensions are absorbing much of the tq from your impact gun, so get rid of the gun, put a bar on the end of your extensions, and give'r hell. They're probably not actually all that tight.
Joined: Sep 2005
Posts: 28,015
Likes: 2,492
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Pulling Engine, Can't Remove Trans Bolts
Remove the distributor and break the top ones loose from above with a 9/16" - 5/8" box wrench that's almost straight with only a slight offset, and flip it over "backwards" to the usual direction. Not a ½" - 9/16" one; the bigger one. Put a 2nd wrench on it to extend it if necessary, probably will take about a 1" or 1-1/8" one.
Supreme Member




Joined: Sep 1999
Posts: 3,046
Likes: 825
From: Colorado USA
Car: '83 Firebird (T/A Clone)
Engine: 350 with L-69 components
Transmission: 700R-4, 2000 RPM stall converter
Axle/Gears: 10-bolt/3.73 ..
Re: Pulling Engine, Can't Remove Trans Bolts
That's strange. They're only supposed to be torqued to 25 ft.-lbs.
I had no trouble removing mine...
I had no trouble removing mine...
Supreme Member




Joined: Oct 2000
Posts: 3,239
Likes: 809
From: Park City, UT
Car: '92 Corvette, '89 1/2-a-'Vette
Engine: LT1, L400
Transmission: ZF6, T5
Axle/Gears: 3.45, 3.31
Re: Pulling Engine, Can't Remove Trans Bolts
Maybe. I grew up in New England....lots of rust there. Never found rusted bellhousing bolts that presented a problem. Even worked in a salvage yard in New England for a few years....pulled apart a LOT of engines/trans' doing that job. Can't say rusted bolts were ever an issue. Either way, his impact tq is probably getting killed by extensions, he just needs a big bar and some grunt
Senior Member




Joined: Jul 2016
Posts: 810
Likes: 224
From: az
Car: 91 WS6 GTA
Engine: 5.3
Transmission: 4l60e
Re: Pulling Engine, Can't Remove Trans Bolts
if theyre being that hard, itll be easier to pull the trans with it.
it sucks, but, the job will be easier in the end
it sucks, but, the job will be easier in the end
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Supreme Member




Joined: Sep 1999
Posts: 3,046
Likes: 825
From: Colorado USA
Car: '83 Firebird (T/A Clone)
Engine: 350 with L-69 components
Transmission: 700R-4, 2000 RPM stall converter
Axle/Gears: 10-bolt/3.73 ..
Junior Member
Joined: Jun 2023
Posts: 4
Likes: 2
From: Phoenix, AZ
Car: 1982 Firebird
Engine: 350
Transmission: 4 Speed
Axle/Gears: 323:1
Re: Pulling Engine, Can't Remove Trans Bolts
A few hints here: The bolts are corroded in the bell housing due to steel in aluminum. GM used at least grade 3 hardened bolts so they should not break. They have a 19mm (3/4") heads on them. Pull the distributor and the cross member for the transmission so that you can tilt the engine back and get on the bolts with a good socket and impact or breaker bar. Try to avoid using an extension because it will steal some of the torque. If you can give the bolts a good smack or or two with a hammer it may break up the corrosion. You can also try heat. I worked as a mechanic while in college up in the rust belt and never had ones that wouldn't come out. You can do it.
Thread Starter
Junior Member

Joined: Apr 2025
Posts: 21
Likes: 3
Car: 1986 Trans Am
Engine: 350
Transmission: 700R4
Re: Pulling Engine, Can't Remove Trans Bolts
Thanks for all of the replies. Went in for round 2 tonight, so far we've gotten 3 of the bolts loose- the two top most and the one lower bolt on the driver's side. After about 3 hours of wrenching on them with open end wrenches, ratchet wrenches, ratchets, breaker bars, impacts, tons of PB blaster, propane torch... the others still won't budge. Pulling the entire trans is not an option, I just don't have the tools necessary unfortunately.
My buddy's dad said try jacking up the transmission a bit, I'm going to try that tomorrow. Does anybody have any other suggestions?
Also, my dad told me that he had work done on the transmission probably about 30 years ago, so it may be possible that the guy torqued the hell out of them. I don't really know at this point, I'm kinda at a loss. I've put so much time and effort into this thing and I've got 3 bolts holding me back from pulling the motor lol.
My buddy's dad said try jacking up the transmission a bit, I'm going to try that tomorrow. Does anybody have any other suggestions?
Also, my dad told me that he had work done on the transmission probably about 30 years ago, so it may be possible that the guy torqued the hell out of them. I don't really know at this point, I'm kinda at a loss. I've put so much time and effort into this thing and I've got 3 bolts holding me back from pulling the motor lol.
Joined: Apr 2010
Posts: 514
Likes: 44
From: New Jersey
Car: 87 Monte Carlo SS
Engine: 89 350TPI Transplant
Transmission: 2004r
Axle/Gears: 3.73
Re: Pulling Engine, Can't Remove Trans Bolts
Or the mechanic used red Loctite on the bolts. Yikes! If so, the fasteners have to be heated to about 425 degrees F to break down the red Loctite.
Fred
Fred
Supreme Member




Joined: Jan 2008
Posts: 1,336
Likes: 567
Car: 1986 IROC Z
Engine: 5.0 TPI
Transmission: 700R4
Axle/Gears: 3.23 Posi
Re: Pulling Engine, Can't Remove Trans Bolts
Supreme Member




Joined: Oct 2000
Posts: 3,239
Likes: 809
From: Park City, UT
Car: '92 Corvette, '89 1/2-a-'Vette
Engine: LT1, L400
Transmission: ZF6, T5
Axle/Gears: 3.45, 3.31
Re: Pulling Engine, Can't Remove Trans Bolts
Are you saying that with:
Wobble socket,
Extensions
Breaker bar
....you can't get 'em loose??
I wouldn't waste my time dicking around with open end wrenches. You need a long lever arm...not a 10" or so, one. If an actual, decnt breaker bar and some muscle isn't getting it, then you need to heat the block. Don't waste time with PB blaster...it ain't even gonna reach the threaded part of the bolt, it makes a mess and fire when you try to heat the block. Skip it and go straight to what works. HEAT. HEAT it (the block, where the bolts thread into it...NOT the heads of the bolts). HEAT it up. HEAT the WEE out if it! If you're stuck using a propane torch (no hot enough), then you're going to have to leave the torch pointed at the block at each bolt location, for IDK....4-5 minutes to get a decent amount of HEAT into that part of the block. Keep the torch focused on that part of the block, to keep it HOT....then? break the bolt free, spin it out and move your torch to the next bolt location in the back of the block. HEAT the block around the stuck bolts and they'll come right on out of there. HEAT it. Not a little....HEAT it up, a LOT.
Re: Pulling Engine, Can't Remove Trans Bolts
You will be victorious over the remaining bolts. Heat is the answer, like previously mentioned. We have modified wrenches to reach such nasty fasteners.
Good Luck!
Good Luck!
Joined: Apr 2010
Posts: 514
Likes: 44
From: New Jersey
Car: 87 Monte Carlo SS
Engine: 89 350TPI Transplant
Transmission: 2004r
Axle/Gears: 3.73
Re: Pulling Engine, Can't Remove Trans Bolts
You should consider using Mapp gas instead of Propane. Mapp gas has higher heat output.
Fred
Fred
Supreme Member




Joined: Oct 2000
Posts: 3,239
Likes: 809
From: Park City, UT
Car: '92 Corvette, '89 1/2-a-'Vette
Engine: LT1, L400
Transmission: ZF6, T5
Axle/Gears: 3.45, 3.31
Re: Pulling Engine, Can't Remove Trans Bolts
^Agree^.
I mean...he should use an oxy/acetylene torch. Lesser torches work, but take more time.
I mean...he should use an oxy/acetylene torch. Lesser torches work, but take more time.
Thread Starter
Junior Member

Joined: Apr 2025
Posts: 21
Likes: 3
Car: 1986 Trans Am
Engine: 350
Transmission: 700R4
Re: Pulling Engine, Can't Remove Trans Bolts
Update: I finally got the rest of the bolts out. There was no loctite on them, nor did they appear to be corroded. Just ridiculously tight. What I ended up doing was loosening the crossmember supporting the trans, giving me just barely enough clearance to fit my breaker bar up there and it was able to get them loose. Thanks again for the suggestions.
Senior Member




Joined: Jul 2016
Posts: 810
Likes: 224
From: az
Car: 91 WS6 GTA
Engine: 5.3
Transmission: 4l60e
Re: Pulling Engine, Can't Remove Trans Bolts
Joined: Apr 2010
Posts: 514
Likes: 44
From: New Jersey
Car: 87 Monte Carlo SS
Engine: 89 350TPI Transplant
Transmission: 2004r
Axle/Gears: 3.73
Re: Pulling Engine, Can't Remove Trans Bolts
Update: I finally got the rest of the bolts out. There was no loctite on them, nor did they appear to be corroded. Just ridiculously tight. What I ended up doing was loosening the crossmember supporting the trans, giving me just barely enough clearance to fit my breaker bar up there and it was able to get them loose. Thanks again for the suggestions.

Fred
Re: Pulling Engine, Can't Remove Trans Bolts
I have one of these extensions that lives solely for this purpose! Hasn't been used in forever, but that's a different story.
Joined: Jan 2005
Posts: 1,404
Likes: 200
From: S. UTAH
Car: 1989 IROC-Z 305 LB9 AT Convertible
Engine: LB9 305
Transmission: AT
Re: Pulling Engine, Can't Remove Trans Bolts
I believe you meant GADE 5 BOLTS. THREE hash marks on the head of the bolt is Grade 5.
Last edited by mikeceli; Mar 31, 2026 at 08:13 AM.
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