simpsonracing

I have a 1987 Silverado 4x4 that has been in the shop four times in the last 10 months for losing 3rd and 4th gear. Every time it has been rebuild and only lasts a month or tow then 3 and 4 go out again. The last time it was in the shop the guy had it for a month but the truck was good to go.

Today it lost 3rd and 4th again and I am pissed. I cant seem to go 3 months without this truck being in the shop for a transmission problem. I love my truck and want to try and figure out a solution.

I have heard a turbo 400 will mount up with an adapter plate being it is a shorter transmission. At this point I am don't with the Overdrive and want this thing fixed right to where I don't have to take it to a shop again for at least a couple years.

The transmission is under warranty for about another 2 months after that I am on my own. Would it be better to get this Transmission rebuilt or go for a proven 350 or 400 instead and ditch the over drive. Keep in mind with warranty this will be the fourth time this truck has been in the shop for a transmission problem in the last 10 months and I am tired of it.

This guy claims he has been building Transmissions for the last 40+ years and my family has been going to him for at least that amount of time. He is a great guy but I am thinking of cutting my losses and going with a different Transmission guy.

Allan In NE

Can you put up a picture of this truck to give me some idea of what we're dealing with here?


There is a huge difference in simply replacing parts and actually knowing how they work and what you are doing.


Allan

simpsonracing

I apologize for not giving details. Its a 1987 Silverado with a 700R4. when the problems first started the truck had 3:73 gears in it. It now has 3:07's in it. It would never get into 4th gear until today. I got it on the freeway and got it into 4th gear then I was going up a small hill. It shifted into 3rd and I accelerated then it shifted back into 4th. After that it was all over it spun 4th gear and revved to like 6,000 rpm and 3rd and fourth were done.

I have been doing some research with a company that claims they can build a 700R4 for about 2300 bucks but you can buy the parts that they build it directly from them. They are calle0d PATC they seem to be ligit and I am wondering if I were to invest the 500 dollars+ into this tranny if it would be worth it.

PATC claims they have a transmission in a 900hp car for the last 2 and a half years that is still holding up. these guys seem to know what they are doing so should I even go there.

here is a picture of my truck it is a 1987 Silverado 4X4 the Transmission is the only problem I have had since I got the truck just over a year ago. Any and all help is much appreciated.

Allan In NE

Okay, one more thing.....

Pull the dipstick and see if the oil is discolored and/or if it has a "clutchy smell" to it.

Since it's only been a few months since the last repair, it ought to be absolutely pristine.....pink and no smell.

Has the shop shown you what they found on each repair? I can walk you thru this, but first need to know exactly what is wrong with the transmission before we go any further.

Thanks,

Allan

simpsonracing

I apologize for not getting back sooner. I actually checked the fluid as soon as i got home it is full to the correct level and looks brand new. There are no discolorations or small chunks of clutch materials in the fluid. Every time the transmission has been in the shop the guy told me it had smoked 3rd and 4th gear clutches.

Anytime I have blown a transmission there has been clutch material in the fluid so this is kind of weird to see. The fluid still smells sweet like it is brand new also. I have been told there is probably a snap ring that may have not gotten put back in for the 3-4 clutch pack. I have also been told the 3-4 clutch pack has a servo that has a ride ring on it that can over heat and warp making minimal contact with the clutches and make them slip.

Either way every time it has gone it has been the 3-4 clutches and never anything else. I still don't understand why there is no material in the fluid though. I have been watching videos on-line of how to rebuild one myself and I am seriously contemplating it. I am a pretty experienced mechanic and I know there some special tools but this problem is getting old.

Any and all help is appreciated gentlemen thank you very much.

Allan In NE

Will this thing ever catch third, or is it just totally gone now?


Allan

simpsonracing

No 3rd and fourth are totally gone. As soon as it shifts out of second going to third it slips and then free revs. It doesn't catch any part of third gear.

Allan In NE

You REALLY, REALLY need to bring me that transmission.

However, let me list the failures in order of occurance:

1. Most important! Fuel Filter. Neither you nor the engine can tell it's plugged, but the transmission can. Take it off and see if you can EASILY blow thru it. When they are plugged, the truck will feel like it's stuck in 2nd gear or rapidly shifts from 3rd right back to 2nd and seems to stay there.

2. Governor driven gear is apple-cored. Remove the round cover, pull it out and inspect. HOWEVER, your tranny guy would have caught this, I'm sure.

3. Stuck TV cable. Does it retract normally and move freely?

4. Stuck throttle valve........you don't want to go here.
4a. 3 and 4 results in high line pressue....the thing can't upshift.

5. Burned 3-4 clutch. If this guy has failed again, THERE WILL BE SOOT in the bottom of the pan, I promise you. Drop the pan, pull the filter, put it in a vice and break it apart. Look inside the folded paper element for signs of burned clutch material. Further, if this clutch is toast, there is a reason behind it. More often than not, this results from an incorrectly adjusted TV cable.

6. Forward sprag. During the 2-3 shift, the "load" is transfered from the low roller clutch to the forward sprag. If this guy freewheels (slips), there will be no upper gears because the transmission is still pushing against that low roller clutch.

7. Leakage at the forward accumulator. The axle will completely come out of its bore and the result is a huge hydraulic leak... As soon as you drop the pan, look to see if this little axle is protruding out of the slot in the accumulator cover; it shouldn't be. Although, this failure usually shows up first as a slipping or 'grabby' 2nd gear.

Don't be too hard on your tranny guy. These things can sometimes bring a grown man to his knees with tears in his eyes. Since he's been thru this thing a number of times, I feel he is just over looking or missing the root cause of the failure.

Allan

simpsonracing

I drove the truck today to warm it up and check fluid again. When I put the shifter in second gear the truck shifts hard as hell. The fluid looks great and when the shifter is put into overdrive it goes from second gear to free rev.

The tranny is still under waranty so I need to figure out if it should go back to the shop or if its worth trying to figure out myself.

Like I said before every time its been in the shop for the same reason the 3-4 clutches have been toast.