Transmission build

[flyin6]

I am in the process of building my transmission for a 600 HP P-Pump motor for my 91

It is all documented here:

http://real-man-truckworks-and-survival ... ic=458.225

Thing is very little is coming out within the proper clearances.

History: I went to RevMax and told them I needed the parts to build a transmission to hold 700 HP. $4200 later in parts, I began to upgrade the A518. It has every good, better or billet part made and a great low stall converter along with a billet flywheel and even ARP flywheel bolts, a deep pan and a way bigger trans cooler.

Following the RevMax guidance I installed the extra clutches in the OD section and darn if the clearances are way more than they allow. Same thing happened with the low/reverse clutch pack. The only one that came out right was the direct clutch pack at .038 with the called for clearances being .025 to .045"

Here's the weird part, the direct clutch had 4 clutches and 4 steels factory. RevMax supplied a much thinner (.086") pressure plate and 6 clutches and 6 steels. SO when I put the 6 + 6 into the drum, there was no room for a reaction plate! None!
But by just finishing with a steel and placing the wavy snap ring in the groove, I came out with the .038" which is good to go.

Can I run that clutch pack without a reaction plate?

Next, when I pulled apart the low/reverse clutch pack and removed the factory piston it did NOT have an inner seal! Nada...nothing. I used a new billet piston and fitted a new flanged seal in there, but it was a holy terror fitting it.

When I built up the next assembly, the one with the sun shell and my pretty new billet shaft and measured that clearance, it came in at .050" The manual says the max is .048" so that is out as well.

I'll say, anyone thinking of building their trans themselves, you are in for a ride! It is not easy!

[cmann250]

Are you using an ASTG manual? I'm remembering and reading some different stuff in my book.

Is the direct clutch you are referring to in the main case or the O/D case?

[txs]

absolutely not, you gotta have the reaction plate.

[txs]

I believe what you're calling the low and reverse clutch is referring to the front clutch retainer, the inner lip seal is in the retainer, not the piston.

[flyin6]

I threw in the towel

Took the transmission over to Pro-Transmissions in Erlanger KY

Nothing was coming out, but I have been given so much bad advice from the guys who sold the parts that I really don't know anything else to do.

For example they had no idea how the clearances in the OD unit could be that far out, yet I checked and rechecked to make sure the stack up of parts was correct, and it was.

Then in one of the clutch drums where the factory called for 4 clutches and 4 steels, RevMax sold me 6 of each. Then they stated they would fit, but when I added their 6 + 6, there was no room for a pressure plate or a reaction plate, just another thin steel. The owner of Pro Transmission said there was no way that 6 clutches would fit of that size.

Further the rear drum band piston. I asked RevMax why they didn't send me a better one. Frank told me that there was no such thing as an aftermarket one, and that's why they do not supply one. I searched and found a steel aftermarket piston with a better seal and a iron piston ring for $42, so I ordered it.

I just kept getting that sort of wrong or bad advice from RevMax and felt that either they or the factory was in error. I had the ATSG and the 1991 FSM on hand for the build. I referenced both although the FSM is 10 times better, and the instructions and especially the clearances differed a bunch from RevMax. The differences were so significant that sometimes the factory clearances were not even in the range of the FSM! So who do I believe? The factory that built the thing?? OR a company that makes some of the parts, parts that do not fit.

At the end of the day, I decided not to play RevMax any longer and go get professional help.

I will say that attempting to build a transmission yourself is an iffy proposition. When the clearances do not come out and the FSM calls for you to go find a thicker snap ring...well, good luck with that.

The good news is that these guys at pro transmission know this box very well and pointed to all sorts of things they can do and liked about the trans. Mine actually came from the factory with a 5 pinion stuff and straight splines instead of the angled stuff, and I added all the billet shafts and gears I could along with a billet piston, and every other good part I could find, so this trans will scream when properly assembled.

I just hope the RevMax torque converter isn't like everything else they sent!

[flyin6]

Transmission is done!