48 re 1-2 gear hunt

[ColoradoKing]

Thanks. I'm loathe to contact ATS, but I guess it's part of the trouble-shooting solution.

 

[DogramTD]

See post #3 on this thread. The top one is here, PATC 46RE 47RE 48RE Transmissions, Performance Transmission A518, 518, search the page for #REC. This one uses the GM solenoid.



The bottom one is here, Sun Coast Converters Diesel Transmissions, Fort Walton Beach FL, under Kits & Components. This one uses the Borg solenoid off of the 68RFE units.

Which one seems to have had the best results? The 68RFE one from SC is a few bucks cheaper.

 

[cerberusiam]

Which one seems to have had the best results? The 68RFE one from SC is a few bucks cheaper.

The GM one from PATC can cause some hard shifting in certain builds. Everything I have heard about the Suncoast one has been positive.

 

[drice]

Anyone know of any more specifics on the TTVA Mod

 

[cerberusiam]

Anyone know of any more specifics on the TTVA Mod

Which mods particularly are you thinking about?



The TTVA is only on the 05+ trucks so not sure if thats the correct terminology for what you want.

 

[drice]

Specifically how to advance the gears in the TTVA - have a 06 that 2-3 shuttle shifts alot. Or is there a better way to increase tv pressures?
Thanks

 

[cerberusiam]

Specifically how to advance the gears in the TTVA - have a 06 that 2-3 shuttle shifts alot. Or is there a better way to increase tv pressures?

Thanks

Yeah, I have heard that works and its relatively simple. When I get enough time I was going to do it and document the porocess. Wife might throw things if I take the truck apart again to soon.



What do you have done to the 06 trans? The TTVA mod and the shift enhancer are the only ways I know of to ramp the TV pressure in relation to the APPS. The other mod that seems to be working is a constant pressure VB but that may entail other changes to function correctly.

 

[drice]

Just purchased the truck used. AAmco went through the trans for the previous owner last november and put in all "heavy duty" including a shift kit($4400) but i have as yet been unable to get any more specifics than that. I have put a new transducer and GM gov sol conversion that help a little but not alot
Thanks alot for the help!

 

[cerberusiam]

What are you running the enhanser on?



I am runnig the tow setting on the shift enhancer all the time. Except for intermittent issues which is due I am sure to it being an OE solenoid and having 60k on it, it works well 90% of the time. It will still intermittent shuttle 1-2 under very very light throttle but then quit after it warms. I am running SW6 and Tq Management 3 so it does not take much pedal to get things moving.



The TTVA looks pretty simple and I believe its only a 60 or 70 degree gear thats in there. Should be able to move it one tooth and it will ramp faster with less throttle. I am going to TRY to do mine this weekend and see what happens before I swap out the gov solenoid. Will take pictures and document it.



The other thing you might try is replace the trans output speed sensor. There have been situations where replacing it even though it appeared good has cured some of the crappy shuttle problems. Its another electronic piece that is key to get all the inputs right so the trans works like it is supposed, gets ignored because it seldom will show bad.

 

[drice]

Not running an enhancer - wondered if the would help though. Just being cheap if a simple mod to the TTVA would fix. Run on sw6 as well.
Will love to see pics if you get to it. Cant get it in my head until see it or take it apart myself.

 

[GreasyCummins06]

Ok, I think I may be having the same hunting problem. Mine started towards the end of a 6000 mile 24k pound towing excursion with my '06 2500. I know... overloaded, that's why I thought it was the torque converter gone bad. I thought maybe it was locking and unlocking towards the top of 1st and mid-range 2nd gears. When I first noticed it I was accelerating from a stop and I thought my trailer brakes were on because she just wouldn't go. I managed to get her off the road and checked the fluid, (fluid isn't too badly burnt). transmission service at 40,000 miles now up to 68,000 miles. Has anyone experienced this? The hunting makes sense but why does it sometimes feel like the truck is pulling a sled/braking. I'm trying to decide what to do with this truck now. Maybe my opprotunity to put in a Bad *s* transmission and converter. Or maybe trade her in and let the dealer take the hit. Problem is I just can't afford to do either! Please help if you can. Thanks.

 

[drice]

Worked on the TTVA today. Here is what I did...
Removed the TTVA
The lower cover was removed - Metal cover that is clamped with metal tangs. Remove cover carefully so the gears do not fall out. At first moved the final drive gear (one that attaches to the trans) counterclockwise (looking at the actuator up side down) - this resulted in two codes after assembled (1751 and 1754 i think) WRONG way. Removed and adjusted two teeth CLOCKWISE (net adjustment one clockwise) and reassembled. Trans holds gears slightly longer. Seems to have helped the searching alot but only had time for a short test drive. Will report more in a few days...

 

[cerberusiam]

Great job!!! I did not get to mine since it was busy all weekend. Mine is also shifting funny again so its time to replace the solenoid. Now just gotta find the new BW one and see if t makes a differnce.

 

[drice]

Thinks to himself after finishing >>> pictures would have been nice bonehead. -Sorry Its a 20 minute job and very easy as long as you know to go clockwise...
Drove it more today. Little to no shuttle shifting. Does drive different though. Better I think. Not quite such a race to overdrive. Its my understanding that this shifts the tv to gov press ratio and changes shifting points right. Any other affects?

 

[DogramTD]

I just advanced my TTVA as well and it made a positive difference. My trans used to shift into OD on light pedal very quickly (about 30-35 MPH); it seems to have been cured. Will take a bit more time in the pilot seat to tell for sure since I only went up and down the street a couple times.

 

[p-Bar]

Keep us all posted may be something I want to do too

 

[JPul]

I'm just bringing this back to the top to see if there are any further positives or negatives regarding the TTVA adjustment.



When towing my 9K 5th in tow/haul, I would like to wind a little higher in 3rd locked before the shift to 4rth OD locked. At lighter throttle, this is happening at 50mph and the rpm is just a little low at 1500 with my 3:73.



As well, is there a simple change to get a more distinctive shift pattern from start, than the feeling of constant rpm, steady speed increase or this just the nature of the sloppy TC in the stock trans.



Regards, John

 

[cerberusiam]

When towing my 9K 5th in tow/haul, I would like to wind a little higher in 3rd locked before the shift to 4rth OD locked. At lighter throttle, this is happening at 50mph and the rpm is just a little low at 1500 with my 3:73.



As well, is there a simple change to get a more distinctive shift pattern from start, than the feeling of constant rpm, steady speed increase or this just the nature of the sloppy TC in the stock trans.

Lock out OD until you want to shift then engage it again. Best way to cure that easily.



Use TH, that will give you better shift distinction, extend the shift points, and a more aggressive lockup pattern.



Beyond those simple things, a lower stall TC and a shift kit will address all that also.