Tranny question for the experts

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Sep 6, 2001 | 05:48 PM

R.C. Righter

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Joined: Oct 1999

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From: Ashburn, VA, USA

Tranny question for the experts

Okay ... it looks like my 700R4 is (finally) about to bite it. (I don't think it's ever been rebuilt and the car has 194,000 miles on it!) It's an 86. I know that some years are better than others. What years do I want, what years do I avoid, what are the diffs? TIA

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R.C. Righter
86 Trans Am

Sep 6, 2001 | 06:41 PM

Superman

Supreme Member

Joined: Jan 2000

Posts: 1,301

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From: Panama City Beach,Florida

Car: 1989 Camaro

Engine: 406

Transmission: Pro-built 700R4

I am by no means an expert,but the 82-84 700R4's were the 27 spline and the 85-91 were the 30 spline which make them a bit stronger.

Sep 6, 2001 | 07:01 PM

Mark A Shields

Supreme Member

Joined: Jan 2001

Posts: 7,164

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From: Someone owes me 10,000 posts

Car: 99 Formula

Engine: LS1

Transmission: T56

Axle/Gears: 342

I believe it was 87 or half way through 87 they changed some internal components of the trans. These tended to hold up better. I am sure someone else can say for sure but if you can find one made after 87 you'll get the new components.

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'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
3" Hooker CatBack w/Aero Chamber muffler
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
3:73 Posi
Rebuilt 700R4
B&M Megashifter, 5" Autometer Tach w/shift lite

Sep 7, 2001 | 04:44 AM

transfixleo

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Joined: Feb 2001

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From: Webster, N.Y.

194K? If it doesn't need anything more than a soft parts O/H why not just build that one? It seems to have proved itself. It will have the 30 spline but it won't have the Aux. VB. I built an '82 core for a car I used to have and after I was done with the car I sold it to someone. Well that unit is still on the road and has clocked over 200K since I built it. Don't be too afraid of the older cores as it is more important to have someone build it that knows what they are doing than worry too much about the year. JMO.

Sep 9, 2001 | 06:10 PM

JP84Z430HP

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Joined: Feb 2000

Posts: 1,416

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From: Johnstown, Ohio

Car: 84 Z28

Engine: 355 (fastburn heads, LT4 HOT cam)

Transmission: 700R4

Axle/Gears: 9-bolt, 3.27

I totally agree with Leo on what he says, but if you are looking for the best core to build upon, the '88-up is about the best, along with some of the updates out there (such as the 3-4 clutch pack that changed in the 90's). I have aquired an 88 Iroc for parts, so I'll build that tranny for my car, along with the rear, and the TPI setup. The car has all that I need!

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Working on:
'84 Z28 LG4 305 with 208,000 original miles!
Dual electric fans (from a formula).
145 MPH IROC Speedo
430 HP 350 (ZZ430) Coming soon! (Building it myself, so I don't get those AWESOME valve covers!)

Starting to look like the Kicker poster child!

ASE Certified Master Tech
+ L1 Advanced Engine Performance
+ X1 Undercar Specialist

And....A sig. that's getting way too long!