91.5 tranmission needs rebuild

[KOG]

Started slipping in first under full throttle load, now has no reverse and no engine braking in first which indicates rear band. I need to build this thing stronger than stock to handle either the 240 HP it has now or maybe as much as 300 in the future. Any suggestions as to who to buy rebuild kit from and what low stall converter to use? Will start taking it out in the morning. Is used to haul gooseneck trailer at GCW near 26000 on a regular basis. 3.54 axle, yes I'd like to have a 4.56, but don't. Therefore use 2nd gear at up to 65mph when towing full loads. Might be nice to have an additional cooler as well, but have temp gauge now and watch temp closely, never run over 270 on outlet line to cooler. Also limit EGT to 1200.

 

[DonFitzwater]

Is this a non-lockup converter? If it is, convert to a lockup type. Call Dave Goerend, I'm sure he can walk you through it.

 

[KOG]

Is this a non-lockup converter? If it is, convert to a lockup type. Call Dave Goerend, I'm sure he can walk you through it.

Well, yes, it's not lockup. And the 46RH does not support lockup which is why I was asking for low stall converter info.

 

[cerberusiam]

You will have a log hard road building a 46RH to handle those loads with that gearing. Simply too much TQ thru the trans at double the GCVW it was ever intended for. A simple gear change to 4.10's would make a huge difference. There is simply no way to replace good leverage.

A rebuild and shift kit is going to help but trying to reverse the load is what is killing the rear band, 3.54's and the reverse ratio is too high. A billet servo that minimizes leaks with added pressure will help but you can still hurt it.

If you have used it hard quite likely every single planetary in it is now well worn, all are in aluminum cases and wear quickly under heavy loads. To build one that will take that load requires steel cased 5 and 6 gear ones and are $$$.

The OD gear is straight cut and it needs to change to the 47RH 15 degree style if you wan to use it loaded. Added clutches also needed.

You are not going to solve the temp problem on fluid coupling TC, it will always be pushing temp limits under heavy load. Sure do not need a lower stall one with those gears, you will really unhappy when the engine won't rev fast enough. You need a more efficient TC, somewhere around 85-87% and will get a better stall out of it by design. Problem is that can and will create more heat as it will pass the power better.

Considering the cost you might want to consider a 47RH with a lockup switch for better results. That with gears would make it pretty solid at those weights but you would still have to monitor and drive it.

 

[DVolk]

I think you would be better off with a Allison

 

[cerberusiam]

I think you would be better off with a Allison

No doubt. I is just hard to justify +$10k into a truck that is probably worth less than that. Even a 518 build is going to stretch things.

 

[KOG]

Yep, I'd really prefer to keep the cost in reason on this one as I don't use it that much. I've got a 46RE in a parts truck, but the electronics could be a problem with the early engine in the 91 not having the bellhousing sensor that the RE needs unless I'm confused. And then there would be the TPS to deal with as well. That's the 96 I have listed below for parts. I'll look at it tomorrow and confirm what it's got. It may be an RH because when I drove it home it would shift gears with the 92 engine so it can't be all electronic I don't think.

 

[cerberusiam]

The 46RE gas version is even lighter duty. The electronics take a stand alone controller that needs inputs so it is problematic on an older truck.

If you don't use it much then a good TC, shift kit, and a stock rebuild may be good enough.

 

[MMeier]

Is a manual an option, why not put a NV4500 in it ?

 

[KOG]

Manual is not an option for several reasons. I can shift about anything just fine, thank you, but I choose not to (I used to shift up and down all four speeds of a Ford Jubilee double clutching using a hand throttle when pulling forage wagons from field). I live in an area with fairly serious hills. Have you ever backed a trailer uphill between tight obstacles using a clutch? I didn't think so. A torque converter is much easier on the entire powertrain when starting (even my backhoe has a TC). And other people drive this truck at times, some of whom aren't really good with a clutch or a gearshift.

 

[KOG]

May be time to back up and punt. I looked at the 96 parts truck today. It's got a 4.10 gear, larger exhaust, larger intercooler, lockup. After contemplating swapping all of that stuff into the 92 it might make more sense to work with the 96 instead. I'll still have to figure out how to make the 92 engine talk to the transmission and dial it up to about 300 hp, but that might be easier than the other route. Plus I can just leave the 96 hooked up to the gooseneck trailer and leave the 92 for dumptruck. I'm not yet sure of the transmission in the 96. It's got a "kickdown" cable and I thought the RE didn't have one. And it will shift now which I didn't think the RE would do without electrical hookup so maybe it's an RH. Anyway, I'll sort out which it is and go from there. 92 will get built back stock for low dollar and will be fine running at no more than the 10-11,000 gross as a dump.

 

[cerberusiam]

1996 was the switch over year from RH to RE, late 96 form Jan on should have had the RE and a PCM but the roll over might have some slop. Look at the trans on driver side right in front of the rear cooler line, on the ;edge above the pan rail will be an electrical connection pointing up. If it is a flat 3 wire connector it is an RH, if it is the round 8 wire connector it is an RE. The RE's all had a TV cable until MY2005 when the TTVA motor replaced it.

None of the RE's every really talked to the engine, in 96 and RE had a PCM to control things and all it need was rpm to let it know the engine was running, TPS position, wheel speed, and a reading from the temp sensor to decide if it should drop OD. If you could get the CS on the engine and adapt the TPS\Bell crank to the VE pump, or use the VE bell crank and the 96 TPS, it would work. Have to use all the 96 sensors as I think they were a bit different like the TPS.

 

[KOG]

Ah, that helps. I'll be looking at it again to see what I have.

 

[DVolk]

I back up trailers al the time even up hill its called if its a 4 wd put the t case in low range or add a under over drive