'89 700R4 - Rebuild or Install Reman?

[johnsonmtz]

I had the 700R4 in my sons '89 K1500 rebuilt about 2 1/2 years ago. This was during Covid of course and the shops I knew were over 2 months out on their schedule and reman trannies were back ordered too. I was recommended to a small shop in the area and he could get to the rebuild the following week so I went that direction. The rebuild was about 20,000 miles ago and my son is now driving a different car to college. I'm now using the truck for towing my bass boat and general stuff.

Recently I noticed leaks out of the transmission and found the rebuilder had used a cork gasket on the tranny pan and it was wet all around. I decided to replace the filter and install a rubber gasket and when I dropped the pan found a bunch of clutch material in the bottom of the pan and fine metal on the magnet. The fluid color was not burned, but there was definitely a lot of material in the pan. I went ahead and installed the new filter, buttoned up the pan to the proper torque spec, and topped off the fluid. Then I could see the leaks weren't just the pan as I'm now seeing significant leaks out of the bell housing and with a steady drip as the truck is running. Obviously the front seal is completely shot.

I'm not going back to the same guy because he'll likely say I had a teenage kid driving it for 2 years and it's not his workmanship that caused the problem. I would have no argument there (even though I don't think my son abused it) and considering the price of his rebuild I'm not starting to think I got what I paid for....which was a shoddy job.

The transmission is shifting fine, but I'm concerned the material that's gone through it and been used up means it's not long for the world. I have a reputable local shop that can get to it in a week and they have quoted me $2800 for remove, rebuild, and reinstall. I can get a reman transmission (with warranty) from my local Carquest shop for $1,750 total cost. Of course the reman is me doing the work but that's not outside my wheelhouse.

So let's hear it....Would you folks let the shop rebuild it and save your back crawling on the garage floor, or is the $1,000 savings of the reman worth it? I'm really on the fence here and would like to hear some opinions.

Thanks,
KJ

 

[NickTransmissions]

I had the 700R4 in my sons '89 K1500 rebuilt about 2 1/2 years ago. This was during Covid of course and the shops I knew were over 2 months out on their schedule and reman trannies were back ordered too. I was recommended to a small shop in the area and he could get to the rebuild the following week so I went that direction. The rebuild was about 20,000 miles ago and my son is now driving a different car to college. I'm now using the truck for towing my bass boat and general stuff.

Recently I noticed leaks out of the transmission and found the rebuilder had used a cork gasket on the tranny pan and it was wet all around. I decided to replace the filter and install a rubber gasket and when I dropped the pan found a bunch of clutch material in the bottom of the pan and fine metal on the magnet. The fluid color was not burned, but there was definitely a lot of material in the pan. I went ahead and installed the new filter, buttoned up the pan to the proper torque spec, and topped off the fluid. Then I could see the leaks weren't just the pan as I'm now seeing significant leaks out of the bell housing and with a steady drip as the truck is running. Obviously the front seal is completely shot.

I'm not going back to the same guy because he'll likely say I had a teenage kid driving it for 2 years and it's not his workmanship that caused the problem. I would have no argument there (even though I don't think my son abused it) and considering the price of his rebuild I'm not starting to think I got what I paid for....which was a shoddy job.

The transmission is shifting fine, but I'm concerned the material that's gone through it and been used up means it's not long for the world. I have a reputable local shop that can get to it in a week and they have quoted me $2800 for remove, rebuild, and reinstall. I can get a reman transmission (with warranty) from my local Carquest shop for $1,750 total cost. Of course the reman is me doing the work but that's not outside my wheelhouse.

So let's hear it....Would you folks let the shop rebuild it and save your back crawling on the garage floor, or is the $1,000 savings of the reman worth it? I'm really on the fence here and would like to hear some opinions.

Thanks,
KJ

I'd not use any reman from any of those general auto parts places, who knows what (if any) updating or corrective measures were taken to address common pattern failures. Take it to a reputable shop and find out exactly what they will do to the transmission. Here's a quick list of my 'stock plus' build for folks w/engines up to about 350 HP or so:

- Transgo 700R4 Jr shift kit (I modify it to some extent)
- Vette 2nd gear servo
- .500 boost and .390 rev boost valve
- late model 4L60E bonded steel/rubber pistons and ret spring in the forward drum (aluminum ones like to crack after lots of miles, hard use, etc)
- 88+ I delete the load release springs and run a 4L60E spec 3-4 clutch pack (.105 thick steels, .090 thick high energy frictions)
- new factory accumulator pistons (or Sonnax pinless if a performance build)
- Bushings everywhere, including Sonnax teflon pump bushing and wide rear sun gear bushing
- New wiring harness/TCC solenoid assembly + case connector
- BW frictions everywhere else
- new detent (TV) cable
- Alto wide band and new reverse input drum (will re-use the drum and turn it if it's otherwise in good shape w/the lugs, etc)
- Heat treated sun shell (Sonnax Smart shell for anything high RPM / performance / heavy duty)
- Pump resurfacing to return rotor/slide to correct clearance of .001" between rotor/slide and pump body deck surface; pump cover is also resurfaced and new pump consumables (vanes, rotor guide, etc)
- Sonnax TV plunger and sleeve kit (many of the pre-existing sleeves are worn and poor/no line rise is the result)

- Transgo unbreakable pump rings as an option for any mild-moderate performance build 400 HP+
- Sonnax billet servos (2nd and/or 2nd and 4th) for real high stall/high performance

New torque converter at whatever stall is appropriate (base builds will have a 1600-1800 stall converter).

Also no real transmission builder uses a cork gasket - sounds like it went to a hack or flat rater who replaced just what was wrong and no other consumable soft parts.

 

[johnsonmtz]

Thanks for the info Nick. Yes, I was concerned about the quality of the reman and what weaknesses they address during the rebuild. Originally the 2-3 clutch pack went out which was the reason for the rebuild 2 1/2 years ago. With the extended lead times back then and needing to get the truck back on the road I went with the guy that was available. And, you are correct, now seeing what I have I believe he just replaced parts instead of a complete rebuild with quality components as you listed.

The shop that quoted me $2800 is the same one I wanted to use at that time but I couldn't wait. I don't recall his list of improvements, but when I spoke to him he did mention several upgrades to address weak points. The truck is stock and I intend to keep it that way, but I want to make sure the transmission is reliable. With your suggestion I'm leaning toward the rebuild. Also, without a lift in my garage, I'm really not all that thrilled with the idea of crawling under and doing this right now.

 

[DixieWASP]

I'd not use any reman from any of those general auto parts places, who knows what (if any) updating or corrective measures were taken to address common pattern failures. Take it to a reputable shop and find out exactly what they will do to the transmission. Here's a quick list of my 'stock plus' build for folks w/engines up to about 350 HP or so:

- Transgo 700R4 Jr shift kit (I modify it to some extent)
- Vette 2nd gear servo
- .500 boost and .390 rev boost valve
- late model 4L60E bonded steel/rubber pistons and ret spring in the forward drum (aluminum ones like to crack after lots of miles, hard use, etc)
- 88+ I delete the load release springs and run a 4L60E spec 3-4 clutch pack (.105 thick steels, .090 thick high energy frictions)
- new factory accumulator pistons (or Sonnax pinless if a performance build)
- Bushings everywhere, including Sonnax teflon pump bushing and wide rear sun gear bushing
- New wiring harness/TCC solenoid assembly + case connector
- BW frictions everywhere else
- new detent (TV) cable
- Alto wide band and new reverse input drum (will re-use the drum and turn it if it's otherwise in good shape w/the lugs, etc)
- Heat treated sun shell (Sonnax Smart shell for anything high RPM / performance / heavy duty)
- Pump resurfacing to return rotor/slide to correct clearance of .001" between rotor/slide and pump body deck surface; pump cover is also resurfaced and new pump consumables (vanes, rotor guide, etc)
- Sonnax TV plunger and sleeve kit (many of the pre-existing sleeves are worn and poor/no line rise is the result)

- Transgo unbreakable pump rings as an option for any mild-moderate performance build 400 HP+
- Sonnax billet servos (2nd and/or 2nd and 4th) for real high stall/high performance

New torque converter at whatever stall is appropriate (base builds will have a 1600-1800 stall converter).

Also no real transmission builder uses a cork gasket - sounds like it went to a hack or flat rater who replaced just what was wrong and no other consumable soft parts.

Nick, This is a small world; I am in the middle of watching your 700R4 Teardown and Inspection video on YouTube.

 

[NickTransmissions]

Nick, This is a small world; I am in the middle of watching your 700R4 Teardown and Inspection video on YouTube.

Awesome, man! If you like that, I have a bunch of 200-4R videos that will be published to the channel over the next couple weeks or so...

 

[DixieWASP]

Awesome, man! If you like that, I have a bunch of 200-4R videos that will be published to the channel over the next couple weeks or so...

I am looking forward to watching more of your videos. I enjoy how-to videos on YouTube!

 

[Schurkey]

Don't forget to flush (or replace) the cooler(s).

The shop that overhauled the '700 in my '88 K1500 uses a semi-automated converter flushing machine that displays the amount of restriction in the cooler circuit. Assures that the cooler(s) aren't plugged with debris. They also put a fresh ground strap between trans and frame on every trans they overhaul. The ground strap seems unnecessary to me...but that's what they do.

 

[Hipster]

Parts store? no. Warranty is a crapshoot. Did that once. Got one through Advance for a camaro I had. Kind of hard take the vehicle in for warranty inspection so they can determine if it was installer error when the place that built it is halfway across the county.

 

[johnsonmtz]

Thanks guys. Due to timing, my insanely busy schedule, and your advice I'm really leaning toward letting the shop do the rebuild even though it's quite a bit more money. Hipster is right, sure there's a warranty with the store, but that can be a fight. I have a very good relationship with the folks at my CarQuest shop and I know they would stand behind me, but still there could be a fight between them and the reman company.

Schurkey, I had definitely intended to run solvent through the cooler then flush with trans fluid before connecting, but its still a good reminder.

In the end, if the shop does all the work, there is nothing to come back on me if the tranny fails. Flushing lines, TV cable adjustment, torque converter bolt up, proper filling.....it's all on them. This shop has been in business for years so I don't think they'll be going away any time soon. I don't want to sound snotty, but it's much easier to write a check and drive away than it is to lay on my back in the garage wrestling a transmission, jack, and T-case.

 

[johnsonmtz]

After the rebuild I do intend to tow boats with this truck. Mostly it will be my bass boat (2,500 lbs boat/trailer) and occassionally my runabout (4,500 lbs boat/trailer). Both have hydraulic surge brakes.

I've seen opinions ranging on the 700R4 some say it isn't strong enough to tow a toothpick and others say run the biggest cooler and load it up. The primary advice I keep seeing is NEVER TOW IN OVERDRIVE.

Fair enough, no OD when towing, I can live with that if it means a long(er) life for transmission. I plan to install an external transmission cooler to help with temps when towing. Is there a particular capacity or brand that is preferred for this application? There seem to be endless options and I want to be sure to match the correct cooler. I know it's possible to oversize the cooler causing the fluid to not get up to correct temperature in colder weather.

Thanks