Transmission swap
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From: Bolingbrook IL
Transmission swap
My mom's 1982 Corvette has a transmission with 9YA054N stamped on it which seems to be the typical model for this car. It seems to be having some issues and I have a 1FUM067C that is available to put in if its doable. I believe that it came out of a 1991 Firebird. I would have to change out the tail section but other than that, will the swap work or are there too many internal differences?
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From: Bolingbrook IL
I would search C3 700R4 conversion. That should tell you what is involved. In addition to the "physical installation", you going to need to address the torque converter lock-up of the 700R4 which your current trans does not have.
I've done Turbo 350 to 200-4R and 700R4 swaps in a few F-bodies, but never a C3 so I won't make any comments on that. There are many here who can provide accurate info on that.
I've done Turbo 350 to 200-4R and 700R4 swaps in a few F-bodies, but never a C3 so I won't make any comments on that. There are many here who can provide accurate info on that.
Racer
Joined: Apr 2016
Posts: 494
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From: Bucks County PA
Oh Hey, disregard that that post... You posted 1982, but for some reason, I read 1980.
You are correct. You should have a 700R4 already, so that should make things quite a bit easier and more straight forward. And as a bonus, you'll be able to improve on the older / 1st gen / weaker 700R4 that the 82's had.
Heading off to edit my lat post. Good catch !..
One thing you may want to verify / off the top of my head.. Since you mention firebird, make sure the trans was not from the base 3.1 V6 (which was a 60 degree engine), the transmission case / bell housing area will be smaller than from a V8.. By 91, a lot of the base cars did have the TBI V8, but the 3.1 was still available.
Last edited by 76C3forme; Jul 19, 2016 at 12:25 PM.
Racer
Joined: Apr 2016
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From: Bucks County PA
Both my '91 / 92 F-bodies were the 700R4. Although my K1500 in 89 had a 4L60. I think the F-bodies made the transition around 92 (and then to the 4L60E in 94).
But like fishslayer says, both were the same as they transitioned in during that time period. In fact, there was usually a stamp "4L60" on what appeared identical (and was) to the 700R4 back then.... you may have that stamp on your 91 (possibly)... I remember how confusing it was back then, when GM started changing "the naming"...
Last edited by 76C3forme; Jul 19, 2016 at 12:37 PM.
Thread Starter
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From: Bolingbrook IL
One thing you may want to verify / off the top of my head.. Since you mention firebird, make sure the trans was not from the base 3.1 V6 (which was a 60 degree engine), the transmission case / bell housing area will be smaller than from a V8.. By 91, a lot of the base cars did have the TBI V8, but the 3.1 was still available.
Racer
Joined: Apr 2016
Posts: 494
Likes: 93
From: Bucks County PA
Luckily the Firebird had a V8 LS engine in it. I am pretty sure that the bell housings are the same, at least they look like it at first glance. The tail sections seemed to be the only difference as the Vette has a mechanical speedo and the Firebird is electronic. I just wasnt sure if there may be internal differences that may be lurking such as TV cable functioning, governor springs, etc.
The V8 trans / bellhousing / case will be the same, so you're good there. I have heard that the tail does need to be replaced (but I'm not familiar with that personally).
In the later transmisions , the Corvette automatics got a different servo as well, but coming from an older version, like you have, (to me) it would not seem that, it would be a concern in your case as the tramsmissions went though a few updates over the years and a '91 (in stock form) should be a bit stronger thean your original unit).
I'm sure someone here (with an 82) must have done that "swap" before. Seems to me it would be a bit more straighforward than a 350 to 700 swap.
I'm actually curious now as well. (what any differences are).
I remember doing a trans swap in my wifes 3000GT SL (automatic). I was only familiar with with manual transmissions in my VR4's so I picked up one from 2 model years newer. (A few connectors were different so I had to replace a few plugs etc). ALways something interesting that's for sure.
"Apples to Oranges" though since that was a Mitsubishi, but those are the things that always make things interesting! Changes / updates in suppliers and parts etc. At least your car is originally set up for the 700R4 so you should be in better shape than most. Interested in following along.
Last edited by 76C3forme; Jul 19, 2016 at 02:02 PM.
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Thread Starter
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From: Bolingbrook IL
I'll definitely keep you posted on how things go. Do you think that the bolts that hole the straps of the u-joint to the yoke are anything special such as hardness? The shop that she had some work done at many years ago rounded one of the 12 point 1/4" socket bolts. I can't seem to find the bolts and was thinking of using Allen head screws as they tend to be harder. Maybe harder isn't a good thing also.
Racer
Joined: Apr 2016
Posts: 494
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From: Bucks County PA
I'll definitely keep you posted on how things go. Do you think that the bolts that hole the straps of the u-joint to the yoke are anything special such as hardness? The shop that she had some work done at many years ago rounded one of the 12 point 1/4" socket bolts. I can't seem to find the bolts and was thinking of using Allen head screws as they tend to be harder. Maybe harder isn't a good thing also.
Do your originals have 3 lines (or 6 lines) on them?? Something like this:
http://www.gtsparkplugs.com/ez-read-bolt-markings.html
(Or do they use the E10 External Torx type of bolt on the later C3)??
For me, I'd want to stay with a "normal" Hex head for those. (Especially if they are the E10's which can be a real pain to remove). Allen's may be a bit "tough" to remove after years of use / if they get corroded etc. (not to say they would not work) - but when Allen's "corrode", they also corrode in the center portion where your Allen socket is going to go, sometimes resulting in a "loose fit" of the socket which can cause them to strip.
Last edited by 76C3forme; Jul 19, 2016 at 02:44 PM.
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From: Bolingbrook IL
http://www.gtsparkplugs.com/ez-read-bolt-markings.html
For me, I'd want to stay with a "normal" Hex head for those. Allen's may be a bit "tough" to remove after years of use / if they get corroded etc.
For me, I'd want to stay with a "normal" Hex head for those. Allen's may be a bit "tough" to remove after years of use / if they get corroded etc.
Racer
Joined: Apr 2016
Posts: 494
Likes: 93
From: Bucks County PA
Honestly, I never looked for the lines as the head of the bolts are so small. I couldn't believe that it took a 12 point 1/4" wrench to fit them. Socket wouldn't work. That is a good point about the Allen heads, though. Whenever I think of harder than normal bolts those are usually the first to come to mind.
Hey, You must have replied when I was updating my post. While I was thinking about it, It hit me that you may have the E-10 External Torx on your car. (Which it sounds like you do). I'm not sure about markings on those.
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From: Bolingbrook IL
That could be. I have the correct socket for that but there was no way it was going on unless I took off the diff end and bent the shaft around to make the bolt head area bigger. I wanted to remove as little as possible so I left the back end installed