Help!!! no overdrive after vette/super servo install.

[BananaHANDS]

I've looked quite a bit to find a post addressing this specific problem and couldn't find anything. So sorry if it's double post but I tried.

I installed the vette servo and the 4th gear super servo last night on my 03 z71 5.3 Shifts 1-2 and 2-3 are great very clean but I couldn't get it into 4th gear on my drive to or from work which includes about 10 miles of interstate driving. As far as I know everything went in correctly. I just got off the phone with Superior Transmission, who makes the part(Great customer service by the way, he called me back even after they'd closed), and he thought it might be the lip seal on the servo in a bind or cut. I just got home from work and am waiting for it to cool off before i open it up again.

Has anyone else dealt with this? Any help at all would be greatly appreciated it's my daily driver so i'm a bit desperate.

 

[2000Yukon]

Just take it back apart and double check that everything is there and in the correct place.

When I installed mine I ended up forgetting to put the 3-4 apply plate back in, felt like a bit of an idiot after I figured out what happened.

 

[BananaHANDS]

Got it figured out, this was the culprit, must have got in a bind while I was putting it in. I reinstalled the old one and am waiting for the replacement seal.

 

[BananaHANDS]

Okay so, the guy from superior sent me another Lip Seal and I put it in. It worked for a short test drive, but still no OD on the way to work. So I sent the whole assembly back to Superior and he's going to look at it and see if it's faulty. I can't figure out if i'm doing something wrong while putting it in? I have the lip seal in right and I have the whole thing coated in Transmission Fluid so it will go in easily, but the seal keeps ripping.

The guy from Superior also told me that Oregon Performance Transmission isn't actually an 'authorized dealer' because they Superior products wholesale from a separate distributor and trying to get the issue resolved would be a hassle.

Anyway here's a pic of the second seal that's ripped, any help would be greatly appreciated.

 

[Jay]

The piston is supposed to stay inside of the cover at all times... this almost looks like the piston is slightly protruding from the cover when oil pressurizes behind the piston, making the seal tear on the edge of the cover. Make sure the cover ring is fully seated. You have to be careful here... if the cover isn't FULLY seated, then the ring can come lose and break the case bore housing meaning you will have to buy a new case and swap all the rotating assembly over. Quite expensive.

When installing the cover, push it in until it bottoms the pin out on the band anchor, then push the locking ring into place with the cover bottomed out. You will have to get creative with the trans still in the truck to accomplish this. If you can reach, it wouldn't be a bad idea to take a screwdriver and push specifically on the ring in a few places while the cover is fully pressed in.

 

[BananaHANDS]

Thanks Jay I was hoping you would chime in at some point. I've read several of your other posts and it sounds like you know your stuff!

 

[blueflamed03]

he does!

 

[BananaHANDS]

Okay, talked to the guy from Superior today. He thinks the pin might be too short, but not too short for the stock 4th apply to not work because of it's design. Is this possible? He's really trying to take care of me; he included a pin extender in the box he's shipping back to me plus extra O rings in case I have to re install it a couple times.
It does seem like there's more travel with the stock assembly (approx 3/16 of an inch if I remember correctly) but when I put the Superior 4th apply and cover in there is just enough travel to clear the snap ring.

 

[Jay]

Unless superior machined the piston too thin, I don't see any other reason why there's a geometric issue. If the factory 4th piston works fine, then the superior should also.

Since the factory piston works fine, my first suggestion would be to send the superior back for a refund and use the factory piston. Or upgrade to the sonnax dual piston if you feel the need for a stronger 4th servo (except for towing, it's unnecessary in most cases). The superior 4th piston is only barely larger than stock so you won't feel much of a difference. You will feel a difference with the sonnax since it's much larger than the factory 4th.

With that said, I never used the superior 4th piston, only the sonnax dual piston so this isn't familiar territory. For cars i just used the stock 4th since the 3-4 shift should be avoided at WOT and you can safely block the 3-4 accumulator for an improved shift (do not block any other accumulator in this trans). In trucks the sonnax dual piston works great for towing... that's about all you'd ever need it for. Regardless of servo in use, the band clearance is the controlling criteria.

You do open a small can of worms when changing out to a longer pin. Reason is, you are much more likely to screw up the pin/band clearance. If that gets too small, then you run the risk of having the band drag on the drum all the time which will cause a rebuild in short order.

If the 4th piston truly is coming out of the case cover and tearing the sealing ring, then you might get away with installing a small shim between the outter retaining ring and the superior piston to push it further inside the cover (assuming it isn't already bottomed out). You will have to keep a CAREFUL eye on your band clearance. The normal range is 0.075-0.125" total travel. You may have to do several removal and adjustments (grinding/milling the shim) to get the clearance needed.

For my setups I use the lower end, in the 0.075-0.080 range since this clearance will increase over time as the band material wears. But to that point I had the whole transmission apart and could make adjustments elsewhere to work with whatever band clearance I had as long as it wasn't too small.

Again, I reiterate the importance of getting that cover snap ring seated properly every time. Mess that up once, and the result is a broken case housing. Good luck.

 

[BananaHANDS]

Jay, you were right in your earlier post the 4th apply wasn't in the cover all the way, and it was my own fault because I was trying to put the 4th apply in the housing and then install the cover so it likely never made it inside the cover, hence the decreased clearance. I've got it in there now and it's working fine I just made sure the 4th apply was completely seated inside the cover before install and everything was lubed. I really appreciate your advice, you're like a frickin' encyclopedia. Do you work on transmissions for a living, or do you just happen to be well versed in all things transmissions? (I was going to abbreviate that to trannies but I decided it might get misinterpreted, haha)

I'd also like to mention that Bob White of Superior Transmission was a HUGE help through the entire ordeal which turned out to be my own ignorance. We had several discussions on the phone, and emails and texts after his business hours. He also sent me several extra seals and o rings and even sent a pin extender which I didn't end up using. He definitely went the extra mile to make sure I was taken care of.