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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: zieg85 on May 18, 2022, 04:40:41 PM

Title: 1981 C10 700R4
Post by: zieg85 on May 18, 2022, 04:40:41 PM
A friend of mine has an original 116K mile 1981 Chevy C10 with a 5.0L and 700R4.  Reverse went out.  Would it better to order one versus having this one rebuilt?  I have heard the earlier 700R4 needed internal upgrades.  Would a transmission shop automatically know this being older 41 year old stuff?  Please advise
Title: Re: 1981 C10 700R4
Post by: Mike81K10 on May 18, 2022, 09:15:54 PM
Personally, if it was my truck and the original transmission, I would have it rebuilt by a reliable place/person.
Title: Re: 1981 C10 700R4
Post by: Shifty on May 19, 2022, 09:18:48 AM
Personally, if it was my truck and the original transmission, I would have it rebuilt by a reliable place/person.
What Mike said.  ;)
Title: Re: 1981 C10 700R4
Post by: bd on May 19, 2022, 10:05:56 AM
I agree.  Really, the outcome depends on who does the job.  Use a known dependable shop/individual and you should be happy with the result.
Title: Re: 1981 C10 700R4
Post by: MIKE S on May 19, 2022, 09:48:15 PM
Are you sure it’s a 700r4? The first year for a 700r4 was 1982. If it is all original it would have been a THM350 or THM350C.
Title: Re: 1981 C10 700R4
Post by: zieg85 on May 19, 2022, 09:55:53 PM
Are you sure it’s a 700r4? The first year for a 700r4 was 1982. If it is all original it would have been a THM350 or THM350C.

The shift selector and RPO code sticker in the glove compartment say it is, maybe it is a 82, not 100% sure
Title: Re: 1981 C10 700R4
Post by: VileZambonie on May 20, 2022, 06:39:17 PM
Agreed, no way it's an 81 with an original 700R4
Title: Re: 1981 C10 700R4
Post by: haroldwca on May 21, 2022, 08:49:58 AM
The main issue with the earlier 700R4 is the sun shell.  Think of it as a housing for the sun and planetary gear sets inside the transmission.  Newer units (I think 1987 - later) have stronger sun shells.  When you compare older and newer side by side, the later shells are visibly thicker and noticeably heavier. You can request this specific upgrade when you have it rebuilt. It should be less than $100 upcharge, and it’s a direct replacement.  A 700R4 behind a stock 305 really shouldn’t require much stronger internals, but since it’s a 40 year old transmission and you’re going to be inside it anyway, you might as well upgrade for peace of mind. Have fun and good luck !
Title: Re: 1981 C10 700R4
Post by: JohnnyPopper on May 21, 2022, 05:43:38 PM
Maybe a late '81. What does the RPO say as to when she was shipped out?

Don't know about GM but Ford would start using the next years parts lat in the year.
Title: Re: 1981 C10 700R4
Post by: VileZambonie on May 21, 2022, 07:34:56 PM
All that half year stuff is fan fiction
Title: Re: 1981 C10 700R4
Post by: JohnnyPopper on May 22, 2022, 02:28:09 PM
1955 Chevy trucks series 1 vs series 2 Apache... ;)
Title: Re: 1981 C10 700R4
Post by: VileZambonie on May 22, 2022, 06:18:42 PM
Has nothing to do with these trucks....
Title: Re: 1981 C10 700R4
Post by: zieg85 on May 22, 2022, 10:57:08 PM
Maybe a late '81. What does the RPO say as to when she was shipped out?

Don't know about GM but Ford would start using the next years parts lat in the year.

It is actually a 1982.  Thanks guys!
Title: Re: 1981 C10 700R4
Post by: peewee0413 on July 11, 2022, 11:55:21 AM
A friend of mine has an original 116K mile 1981 Chevy C10 with a 5.0L and 700R4.  Reverse went out.  Would it better to order one versus having this one rebuilt?  I have heard the earlier 700R4 needed internal upgrades.  Would a transmission shop automatically know this being older 41 year old stuff?  Please advise
Some tranny shops build back close to factory. Performabuilt 700r4 or 4l60e if you want an easy controller like US Shift Quick 2 or Quick 4 that is easily, and I mean easily tunable.. Unless you have a performance engine, higher stall converter, the stock tunes on the US Shift work perfectly.

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