New Transmission time...

[Beltran]

The US Gear Aux trans has bearing problems. So I am looking to replace the TH400 + US Gear transmissions with a single 4L80e.

Hughes Performance was recommended. They seem to know their stuff and even recognize a 88 Motorhome on P30 chassis.

Quote for the super tough trans, TQ and controller is over 6k.

Anyone else have experience here with this supplier or have another supplier suggestion I should consider before making this investment?

[cmadmaxman]

Peter had put that setup in his 350LE. We have the controller that came with GM. Both of our rigs was stock 4L80E.
You need to make sure that they have the tail housing that accepts the E-Brake. The 400 one will not work. Use their recommendation for the controller.
I used their torque converter on my 400 build and was very pleased with it.
I also think the transmission mount will need to be moved back, and the first drive shaft will need to be modified.

[Beltran]

I agree with your list. I asked them to make sure the output shaft has a threaded hole for the 18mm bolt to hold on the drum and yoke. They seem to have thought about all of these items.

I will be using the mechanical control unit attached to the carb, then to the electronic control unit.

They had a core already to build from.

[choctawmel]

Originally Posted by Beltran

The US Gear Aux trans has bearing problems. So I am looking to replace the TH400 + US Gear transmissions with a single 4L80e.

Hughes Performance was recommended. They seem to know their stuff and even recognize a 88 Motorhome on P30 chassis.

Quote for the super tough trans, TQ and controller is over 6k.

Anyone else have experience here with this supplier or have another supplier suggestion I should consider before making this investment?

I switched to the 4L80e some years ago and had trouble keeping it cooled. Used the wrong (stock) torque converter. changed that to a multi clutch high stall one then some little $2 piece that wasn't supposed to spine did and it shelled out. Never liked it, more because of the controller from TCI. I changed to a T-1000 6 speed after I put a Cummis 12 valve in it about 6 years ago.
Must say I've been hard on transmissions. I've burn up:545 Allison, 4L80e and the first T-1000 Alison.

[Airdelroy]

I think Im in a similar boat. I have a US gear with TH400. Not sure whats up, but the US gear is just not turning the drive shaft.


Thinking about upgrading the trans to a 4 speed and dropping the US gear. What did you decide and how did it workout?


thanks,
Aaron

[Beltran]

I have a brand new Hughes transmission sitting in the garage, waiting for warmer weather. I can still move mine, but I know that the bearings are failing and I will make the swap in the spring.

[Airdelroy]

Care to share details on what you decided on?


thanks!
Aaron

[Beltran]

Invoice attached
Doesn’t include shipping
This was built to specifications with the ability to support towing a jeep behind the 345.

I opted for the tcu kit that attaches to the stock carb.
I have to convert to a digital Speedo. This cannot support a mechanical one.

[choctawmel]

I did the 4L80e w/the TCI controller and was not happy with it. The TCI people have no idea what/how to reset it. Only one guy know and he was never in and his voicemail was always full. My advice with TCI is after they up grade the controller they flush all knowledge of any older hardware.

After I changed to the cummins the 4L80e in 4th gear only gave me a top speed of 65. I went with the T-1000 6 speed. The only issue I've had is the 5th gear solenoid shorted to ground and destroyed the tranny with another trip home behind a big wrecker..... Not pretty. I think it was the rebuild people but they said it was the software people and the software people said it was the rebuilders. Now the software folks are doing the rebuilds themself.
Just my 2 cents worth.

[Airdelroy]

Thanks for the info!


The overdrive was finally pulled off late last week and it was discovered that the spline shaft and mating coupler were stripped. Now I get to figure out how to spend money I dont really have.


thanks,
Aaron

[Airdelroy]

Why not use the 4L85e? Seems like it was built for the larger vehicles.

Thanks,
Aaron

[Airdelroy]

I see prices that vary for the 4L85e, but seems to be comparable to the 4L80e.


ex: https://gearstar.com/gm-4l85e-perfor...ssion-level-3/


Seems the 4L85e is built for ~18000 GVR vehicles. Can handle higher torque and HP.


Aaron

[Beltran]

Mine was custom built. You’re comparing stock transmission specs. Take a look at their web site and see what they do to the trans and torque converters. Or better yet call them and ask about it.