Author Topic: 1981 C10 700R4  (Read 762 times)

Offline zieg85

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1981 C10 700R4
« 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
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline Mike81K10

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Re: 1981 C10 700R4
« Reply #1 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.

Offline Shifty

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Re: 1981 C10 700R4
« Reply #2 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.  ;)
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Online bd

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Re: 1981 C10 700R4
« Reply #3 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.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline MIKE S

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Re: 1981 C10 700R4
« Reply #4 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.

Offline zieg85

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Re: 1981 C10 700R4
« Reply #5 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
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
https://www.facebook.com/groups/248658382003506/

Offline VileZambonie

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Re: 1981 C10 700R4
« Reply #6 on: May 20, 2022, 06:39:17 PM »
Agreed, no way it's an 81 with an original 700R4
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline haroldwca

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Re: 1981 C10 700R4
« Reply #7 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 !

Offline JohnnyPopper

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Re: 1981 C10 700R4
« Reply #8 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.
1957 Apache 3100 235 Inline 6, 3 on the tree
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Offline VileZambonie

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Re: 1981 C10 700R4
« Reply #9 on: May 21, 2022, 07:34:56 PM »
All that half year stuff is fan fiction
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Offline JohnnyPopper

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Re: 1981 C10 700R4
« Reply #10 on: May 22, 2022, 02:28:09 PM »
1955 Chevy trucks series 1 vs series 2 Apache... ;)
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline VileZambonie

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Re: 1981 C10 700R4
« Reply #11 on: May 22, 2022, 06:18:42 PM »
Has nothing to do with these trucks....
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline zieg85

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Re: 1981 C10 700R4
« Reply #12 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!
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
https://www.facebook.com/groups/248658382003506/

Offline peewee0413

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Re: 1981 C10 700R4
« Reply #13 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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