700R4 problems

[hitechredneck]

Anyone know anything 'bout 700R4's? This is my 3rd one in less than a year in my 90 K5. I had this one rebuilt with "all the good stuff" and now I have no forward gears! Reverse works great, but when I shift to OD, D, 2, or 1, I've got nothing! Please Save Me!

Also have a TH400 out of an 86 CUCV Diesel. Any info on this tranny? I know the filter needs changed, but I am going to swap the 700R4 for the 400. Also going to swap the diesel's axles to the Blazer. (14B FF rear, Dana 60 frnt, with 456 's and lockers.) Would like to swap the hydroboost steering system to the Blazer, but I am concerned 'bout the P.S. pump bolting up and also the booster to the factory master cylinder. Any Ideas?

 

[bigblock72]

What were you doing when it let go this time?
Is this the third completely different trans, or the third over haul?
Who's building them?
To lose forward gears but still have reverse would mean valve body problems, sprag failure or forward clutch malfuntion. I have actually broken an output shaft in a 700 in such a way that it had "teeth" and would grab in reverse but not in forward, but I knew something bad happened when it let go.
Let me know a little bit about the history, a 700r4 should be able to hold up in your application.
Do you have a matching t-case for the 400?
The pump should bolt up the same as the stock p.s. pump
You'll want to match the master cylinder to the brakes that are being swapped. It will be best to get the master cylinder for the same rig the booster and axles came out of so that way everything will work properly, no reason to reinvent/reengineer the wheel.

 

[Avery4jc]

Nope never heard of them.




























Pay for the membership (best $$ you'll ever spend on your truck) and then...
Clicky Clicky <-----------

Holy crud 500+ threads that have something to do with the 700r4!
The search function will be your friend.


Until then, how long has it been since you flushed the tranny and replaced the filter? One major thing you didn't tell us was your setup. What truck, engine, drivetrain, gearing, tires, etc.






-Avery

 

[Avery4jc]

Ok, I just looked it up and it looks like you are running a 90K5 w/ a 14bff/d60 combo and 39.5" Gumbo Mudders. One thing I didn't like to see though was the 4.56's. If you actually run the truck off road then 4.56's aren't going to turn those 40" tires for long with a 700r4, especially if you don't have the TV cable setup correctly.

Did you have the shop setup the cable or did you do it yourself?

-Avery

 

[SLOK5]

I agree to check the TV cable and "SET IT". ( next trans ofcourse as this one seems FUBAR. I just got my GM GOODWRENCH 700R4 trans installed today so Im good for 3 years or 100k miles, that I wont have to worry about spending another dime on it...My 2 cents ....

 

[hitechredneck]

Setup

The first tranny was the stock 700r4. The second tranny came from an 89' Jimmy. It lasted for about a month. The third tranny is the stock 700r4 that I had rebuilt by a local shop.
The setup on the Blazer is still basically stock (other than the lift and tires which are 35") The 14B and the Dana 60 are being rebuilt b4 I swap them out.
When the last tranny went out, I was just driving down the road (nothing major), and then suddenly I heard a loud bang and then nothing. I thought I lost a u-joint, but didn't. Like I said, no forward gears, but reverse works fine. Had to drive 4 miles in reverse to get home. (THAT SUCKED!!)
The TV cable was setup exactly the way I was told and adjusted for the "correct" shift points. Fluid level was fine as well. I have lost no fluid whatsoever out of the tranny eventhough it isn't working.
I have the complete 86 1 ton CUCV truck that has the TH400 in it. The only problem is that it isn't running (glowplugs, I think is the problem), so I really can't really depend on the tranny that's in it unless I drive it first. (Vehicle was hauled here 2 weeks ago.)

 

[Avery4jc]

Hmm something to think about before swapping transmissions is what you plan to do with it. With 4.56's and your 40's your RPM's are not going to be sky high but at the same time that doesn't help you for off-roading because you don't have low enough gears to utilize some torque.

Check out this site...
http://www.4lo.com/calc/gearratio.htm

It can help you make some decisions.

I thought of doing the same exact swap your talking about, my 700r4 is on it's last leg and I wanted to swap in a th400 because even in stock form they'll hold up to more than some "built" 700r4's. Something to keep in mind especially since you have a '90 though is the wiring, vaccuum, emissions (if you have a visual inspection), etc. The best idea we all came up with was to swap the th400 in and T off a vaccuum line over to the modulator valve (since they don't use a TV cable like the 700r4's) and get a kick down kit from any number of automotive places that sells them (no TV cable = need kickdown to drop a gear if you get into the throttle) then just leave my current computer to run a "ghost" 700r4 even thought it wouldn't be hooked up to anything because it runs some smog stuff on my carb but it would think that it would be running your 700r4.

Basically it wasn't worth it for what I do especially since I live in California, the smog inspection probably wouldn't let it fly. Depending on what you do with the truck and how strict your inspections are will decide what you do.

www.maddogtransmissions.com is a great place to check out as well. He has great prices and he backs all his products.

-Avery

 

[daleearnhardt01]

One thing I didn't like to see though was the 4.56's. If you actually run the truck off road then 4.56's aren't going to turn those 40" tires for long with a 700r4,

So running the truck in low range in 1st gear offroad is going to be worse than running the thing on the highway in OD? 4.56 gears with 40" tires isnt a horrible combination.. Thats why there is a multi-speed transfercase.

As for the guy posting the question, do you run a trans cooler?

I really dont see why a 700R4 wouldnt hold up with in his application

 

[Avery4jc]

So running the truck in low range in 1st gear offroad is going to be worse than running the thing on the highway in OD? 4.56 gears with 40" tires isnt a horrible combination.. Thats why there is a multi-speed transfercase.

As for the guy posting the question, do you run a trans cooler?

I really dont see why a 700R4 wouldnt hold up with in his application

Well I have had this exact conversation numerous times on CK5 and basically what everyone agreed upon that with a 700r4 if you are going to wheel, the lower the better as they are "slush boxes".
I have 38.5's (that only measure 37") and we all figured that I would be best off with at least 4.88's but most guys were saying that they wouldn't run anything higher than 5.13's with my setup.

So he has a 700r4 with 40's, 3" taller than mine and he is running higher than the highest everyone suggested for me. You do the math. Sure it would work out but read a little. He has gone through 3 already and from the sounds of it he has had the TV cable setup properly and he hasn't lost any fluid (which likes to kill 700's fast). So you be the judge.

-Avery

 

[NEK5]

The first tranny was the stock 700r4. The second tranny came from an 89' Jimmy. It lasted for about a month. The third tranny is the stock 700r4 that I had rebuilt by a local shop.
The setup on the Blazer is still basically stock (other than the lift and tires which are 35") The 14B and the Dana 60 are being rebuilt b4 I swap them out.
When the last tranny went out, I was just driving down the road (nothing major), and then suddenly I heard a loud bang and then nothing. I thought I lost a u-joint, but didn't. Like I said, no forward gears, but reverse works fine. Had to drive 4 miles in reverse to get home. (THAT SUCKED!!)
The TV cable was setup exactly the way I was told and adjusted for the "correct" shift points. Fluid level was fine as well. I have lost no fluid whatsoever out of the tranny eventhough it isn't working.
I have the complete 86 1 ton CUCV truck that has the TH400 in it. The only problem is that it isn't running (glowplugs, I think is the problem), so I really can't really depend on the tranny that's in it unless I drive it first. (Vehicle was hauled here 2 weeks ago.)

 

[Avery4jc]

Nice eye, I saw that too but didn't think about it. So it sounds like he may be running and trying to wheel with stock 10b's with who knows, 3.08's with his 35" tires.

Thread starter, is this true?

If so then I don't have much more to say. That combo could keep roasting them as long as you keep putting them in.

-Avery

 

[NEK5]

what part of 35" tires dont you understand?

 

[SLOK5]

qoute:The first tranny was the stock 700r4. The second tranny came from an 89' Jimmy. It lasted for about a month. The third tranny is the stock 700r4 that I had rebuilt by a local shop.


Pay for a factory unit $1125.00 out the door if you get your locall GM Dealer to give you a wholesale discount and you have a QUALITY product. And if something does happen in 3 years or 100k miles take it to ANY GM Dealer and it will be fixed NO charge parts AND labor. Its a no brainer unless you like taking transmissions in and out. The 700R4 can last 4 wheelling and survive 100k miles easy if you keep it cool and due the MAINTANCE on it. new filter and flush it every year...... Only way to go if your going to keep it and still drive it on the hyway for trips. I have stock 373 and 33 inch tires and turn 1500 rpm at 55mph, Off road anything to the Dunes here in Pismo Beach to Moab this fall, plus tow the boat 60 miles to the lake alot during the summer and it works great for me!

 

[Avery4jc]

what part of 35" tires dont you understand?

Fixed it ya' old fart. Man, you getting a little stressed now that you too have to start school soon.

-Avery

 

[SLOK5]

oh and I got stock 10b's

 

[NEK5]

Fixed it ya' old fart. Man, you getting a little stressed now that you too have to start school soon.

-Avery

hey i`m not stressed out about school ALRIGHT MAN?!

 

[Avery4jc]

lol, slow deep breaths man, I just finished my first week back and it'll be ok.

-Avery

 

[SLOK5]

You guys really know how to get off topic on a thread....nice

 

[Avery4jc]

You guys really know how to get off topic on a thread....nice

no problem, thanks for adding to it.

Unless he has more questions our work here is done.

-Avery

 

[hitechredneck]

I'm back!

Sorry about not replying. (Computer problems - Router SUX!)
Also, sorry about not giving the info on my setup. I have finally decided what to do about my '90. I'm going to rebuild the TH400 and swap out the 700R4. While i'm waiting for the tranny to get done, I'm going to go ahead and swap the axles as well.
I know that I have to weld on new spring perches to the 14B (off the Diesel) because the spring width is differenct between the 86 CUCV diesel and the '90 Blazer are different. I also have to change the shock mounts on the 14B as well because the are reversed. Where can I buy the shock mounts? I would like to be able to install them from the rear on both sides (rather than having one shock facing forward and the other facing rear). A setup like the one shown in the tech article for the diff ring kit is what I'm after.
Also, Who makes a "Kicker" shock kit for 6" suspension lift? (All spring....NO Blocks). I know the Rancho USED to make a kit, but it was discontinued. Can I make a custom kit using Rancho 5000 shocks or do I have to purchase "special" shock absorbers for this application?
Any info would be appreciated concerning this. Also, any info on what to watch out for during the axle swap would be EXTREMELY helpful.
Thanks again for the help with my tranny "dilemma".
(Oh, BTY, my membership will be submitted shortly.......just thought you would like to know.)