Looking for some help on the transmission front here

About a year ago I bought a used 4L80e with 178k on it, installed a new valve body (TCC valve bore worn out = no lock up) with an HD2 shift kit minus the pressure relief valve since it tends to be problematic (I wasn’t aware at this time of the Sonnax Self Regulating Valve) I installed this into the truck with a Circle D 3200 pro-series converter and it ran flawlessly behind a cam only 5.3.

Fast forward a little over a year to present day and the truck is now sporting an S475 on about 8psi. I took it to the dyno and it performed really well with great numbers but on my way home I was trying some brake boosting/launching on about 3 psi when the truck lost all forward and reverse gears. I got it home, pulled the cooler lines and confirmed the pump was not doing it’s job. I dropped the transmission and confirmed the broken pump gears through the converter seal as well.

As far as the tune goes, I compared my previous HP Tuners file to the new one from the dyno tune and no changes were made in any transmission tables. The only change I could see related to the transmission tune was that all the Torque Management Max Input and Output Torque valves have an additional “1” tagged on to the end (i.e. 1756lbft is now 17561lbft). The tables are not set to stock though as I copied my settings in from a Turbo 5.3/4l80e swapped car with a p01 computer so it’s possible that the tune settings might be allowing too much line pressure as well but I’m not sure how to interpret whether it’s too high or not. I asked the tuner to look over these values when he gets a moment to see if anything looks problematic and I’m waiting to hear back next week. I’ll post my tune file as well if anyone would care to take a peek through the Transmission tables.

I spoke with a local and well known transmission builder in my area about my issues and we both agreed that this was due to runaway transmission pressure since I didn’t install the pressure relief valve in my HD2 Kit. He also stated that they use the HD2 kit WITH the TransGo Valve to stop the runaway pressures on their 1000hp rated 80e’s. I didn’t feel comfortable with buying a built transmission that uses the TG Valve when it’s mostly agreed it’s a POS.

I love working on my truck and gaining the knowledge/experience in the process so I prefer to work on my own transmission. Other than overlooking an easy solution to what would become a broken pump, this transmission has been great for about 6000 miles of travels with track visits and was holding very well to the new power level my turbo has given me.

So a few questions I have following all the above:

• Would destroying my pump cause damage to any of the clutches?

• Do people go for a full rebuild after a pump failure or just replace the pump?

• Do you guys install the TG Relief Valve? What about the Sonnax? Or do neither like I did?

• What else needs checked for damage as I work through the pieces?

Thanks!

 

Here is the tune in my truck

 

since you now boosted and you have the trans out why not just empty it all on a table and inspect everything? 178k on it i would just do the clutches regardless

like you i prefer to do my own work, about a year ago i rebuilt my 80e never been in a trans before a lot of good info in the old inter web vids manuals was a big help was not all that bad, right about 10k on it at this point been all good so far (know on wood)

 

I agree and I had some time to kill last night so I pulled it all apart and checked everything out. The pump gears and body are pretty demolished so they’ll need replaced and the clutches were the original Borg Warner’s from the factory and I’ve had quite a bit of clutch material in the pan. So I’m going to do what you said and just rebuild it while it’s out of the truck.

I was eyeballing Jakes Stage 2 or 3 rebuild kits last night but have a few questions on it so I’ll probably call tomorrow.

What did you use for your rebuild? And what means did you use to prevent runaway line pressure?

Thanks for the response and your input btw

 

I used a local builder for my 80e.

I made one small request while he built it and I have driven it for 2+ years problem free.

He gave me his standard 2yr, unlimited mileage warranty.

 

I’m not opposed to going through someone locally. Here in KC we have some pretty reputable shops which is nice if I decide on that route.

What did you do have done different? Just curious what other guys are doing with their 80’s while mine is apart

 

Internal dual-feed mod.

 

i have a big trans parts supply house "whatever it takes" a few miles from me, i actually gutted my transmission cleaned all the parts and took them over there had a guy the built them for 25 years go over every thing told him what i was doing with the truck (engine swap, HP i was shooting for, strip and mexico nights) he told me what i needed to replace and what clutches to use

off the top on my head i installed Raybestos Stage-1 Performance, full HD2 kit

some here on the forum are not fans of the HD2 kit but the trans i picked up already had part of one installed so my valve body was drilled so i just did the full kit, i have no complaints at this point with it

sorry i cant be more detailed total noob at trans stuff it was my first and at this point only time in one, i didnt buy any extra tools i was able to get it done with what i had on hand but i did weld up a holder to convert my engine stand to hold the case while i worked on it cost around $25

 

So to pick up where I left off: Circle D Converter is on it’s way back and should be here today. Said the marks on the hub where the pump let go looked like it was engaged well and shouldn’t have caused any issues.

I pulled the transmission lines and cooler out and shot two cans of the trans cooler flush in opposite directions until the cleaner was clear then blew out with compressed air

I got with Jakes Performance and spoke with them about what happened and also ordered up a Stage 3 Rebuild with Recal Kit and started pulling everything apart and hand cleaning everything.

I got the rear torrington bearing in the case installed and adjusted the end play to .010 using the thinnest shim that comes in the kit. I have a couple things I’d like a little clarification on though.

I previously had a Trans Go kit so the valve body is drilled. I’ve been trying to decide how I want to plug said hole and would like to know how others have reversed this mod.

Direct clutch clearance is .65 which seems good with the .010 rule of thumb per clutch (Using 6 with no wave plate here). But when I go to measure the forward clutches I get .077 of clearance with no wave which seems excessive. I put the wave plate back in and it’s pushing in to the back of the pressure plate. I’ve tried swapping different thickness steels in and moving things around but it’s either too much clearance or no clearance at all.

Thanks for the help guys

 

Find someone with a belt sander and sand down the steels.