Question about 1988 Chevrolet K1500

3 Answers

GM experts please advise on THM700R4

My main question about this transmission is just how long can one last? I have had to replace the 700R4 in a 1986 GMC pickup because of a completely destroyed bearing, and am now looking at buying a 1984 suburban that is pushing 200 000km, has hauled a trailer, and still SEEMS to be doing fine other than some slightly eratic engaging of the torque converter clutch. How long can I expect this tranny to last, assuming that it has had regular fluid and filter changes, and had the benefit of a cooler? Cameron Walker 1988 Chevy 1500

Posted by on

  • cedar_sound Jul 19, 2008

    i have a new 700r4 transmission, new tourqe converter and my tv cable is set but it wont shift out of 1st gear



3 Answers

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 4 Answers

A build these every day if u got one that works go with it. your erratic lockup could use a higher pressure third gear switch. unless somebody did the checkball in the tcc solenoid trick.

Posted on Aug 17, 2008



Posted on Aug 09, 2008

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 868 Answers

375,000 I believe is the lifetime

Posted on Jun 02, 2008

1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya Mechanic can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US.
click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

I am looking for a thm400 ****** for 70 pontiac would a 1985 gmc sierra ****** work? i have a gm adapter plate , also underneath on right side of trannyon gmc there is no vacuum line does it build up...

The 1985 GMC Sierra transmission is a th700R4 overdrive transmission. The 700R4 does not utilize a vacuum modulator. Shift points are controlled by the T.P. or kickdown cabe. Proper adjustment of this cable is critical to transmission longevity. Your Pontiac, if originally equipped with a th400 transmission, has no means to connect this cable to the carburetor. I would not recommend this transmission swap. Also the th400 and the 700R4 use different sized drive shaft yokes, so your drive shaft cannot be used.

Aug 20, 2011 | GMC Sierra 2500HD Cars & Trucks

1 Answer

I want to put a 700r4 in a 86 suburban 7.4liter for better gas milage.lts a 8 lug so do i have to change the rear end also?

No, your rear gears should match well with the 700R4, which is quite possibly the best automatic transmission ever produced by GM.

Jan 19, 2011 | Chevrolet Suburban 2500 Cars & Trucks

1 Answer

What transmission is in a 1990 corvette?I think it is a 700r4?and if yes will any 700r4 fit ?

No there are different 700R4 transmission, well that not quite true. The 700R4 had many jobs to matted to Corvettes to SUVs, the internals are where the differences were in the 700R4 such as the servo's and boost valve which can be easily replaced. Best thing to do is to got to a Transmission shop that can build a transmissions for your Corvette or buy a replacement 700R4 for your year of Corvette. That is why the shift points and firmness are different in a Corvette then a Cadillac while they both have 700R4 in the 1990's. Be bad for a Corvette to shift like Grandma's Cadillac going to play dingo. Good luck and hope this helps.

Dec 15, 2009 | 1990 Chevrolet Corvette

1 Answer

Detent Cable Positioning ?

this should be done by a pro..the 700r4 is very touchy and the detent cable is your main pressure control..would advise you take to dealer for proper adjustment

Dec 15, 2009 | 1991 Chevrolet C1500

2 Answers

What year transmissions will fit in my 94 jimmy automatic

GM is notorious for one size fits all, so most any 4x4 transmission will fit. I would stick to close years that can provide the same style transmission, like 700r4 or 4L60, so the electrical just plugs in. Hope this helps.

Oct 13, 2009 | 1994 GMC Jimmy

1 Answer

Disassembling 700R4 transmission

I assume you are disassembling to rebuild. A manual is your best bet. Haynes shows a GM auto trans manual,#10360. You could also look at faxonautoliterature. They have the original GM service manual for your truck, which would have a section on auto transmissions. They also list a GM trans rebuild book for that specific transmission. Hope this helps.

Sep 22, 2009 | 1988 Chevrolet C1500

1 Answer

GM experts please advise on THM700R4

If the transmission has never been service "oil and filter changed" All the metal and dirt in the fluid may have caused the transmission to fail. There are valves and servo's that the fluid flows through and when dirt plugs up the passages or jams a valve open causing the transmission to slip slightly would make a transmission to fail. Check the transmission fluid level and condition and also check the transmission kick down cable from the throttle body. Good luck and hope this helps. 

Sep 02, 2009 | GMC Suburban Cars & Trucks

2 Answers

Transmission converter seems to lock and unlock

You may have two problems at the same time. The speed sensor is the easiest to replace. I would check and or replace the sensor. Then if the test drive shows the lock up fluctuating, I would replace the lock up switch in the transmission. Let me know if you have questions. Hope this helps. Rate me highly, please.
RPM Northwest

Mar 21, 2009 | Chevrolet Suburban 1500 Cars & Trucks

3 Answers

Electric transmission

Hi. I have a '93 Chevy Suburban that is on the 3rd transmission. What you probably have is the earlier 700R4 transmission. What you should have is the 4L60E. I have done ALOT of research on these transmissions, and what I've found out is this: the 4L60E is essentially the same as the 700R4, with the exception that the 4L60E is completely controlled by the vehicle's computer. The 700R4 uses a more antiquated valve body with a TV (throttle valve) cable. In theory, you could use the 700R4 if you connect the TV cable and properly adjust it. If it's a 4X4, your speed sensor is in the transfer case, so that wouldn't be an issue. The 4L60E used in '93 and '94 will only work in those model year vehicles, because of the type of shift solenoids used. The newer units used pulse width modulation solenoids, as opposed to the older on/off solenoids. I have run my truck with the transmission unplugged and the engine still runs fine. The major problem with using the earlier 700R4as opposed to the correct 4L60E, would be emissions compliance. If you want to discuss this further, email me at

Oct 27, 2008 | 1993 GMC Sierra

Not finding what you are looking for?
Cars & Trucks Logo

187 people viewed this question

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts


Level 3 Expert

77499 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22306 Answers

Ronny Bennett Sr.
Ronny Bennett Sr.

Level 3 Expert

6927 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides