Allison 5sp: Trans. issue should I scrap or repair??

[dracing70]

So my mother was driving her 05 lly home today. It has a 03 lb7 tranny in it, and has had no problems for about 10000 miles. She said about 25 miles into the trip when all of the sudden, it did not want to go and was making a whining noise and the tranny temp. gauge was pegged. She could not pull over immediately because she was in a construction zone with no pull off so she went at least 2 mile hot. Looks like it blew fluid from the breather and it has a bundle of tranny codes.
0841,0846,1710,1711,1713. Fluid is full and is also burnt good. After cycling the ignition a few times I got it to go and it felt ok, however reverse quickly threw it into a frenzy again. Any suggestions???????

 

[durallymax]

I didn't look up the codes, but if you have time to drop it and tear it apart after running any needed test first, I would. Not often that the costs of fixing a stock Allison outweigh the costs of buying a used one and ending up with junk again.

 

[dracing70]

yeah thats what i wanted to figure out. which is cheaper, as im definately not going to build this one fully. I just need a stocker. the largest problem however is I have no time right now and she needs a vehicle. Two of the codes are pressure codes, one is a reverse code and the other two are solenoid codes. And i know what you mean about taking the chance of getting another junker.

I didn't look up the codes, but if you have time to drop it and tear it apart after running any needed test first, I would. Not often that the costs of fixing a stock Allison outweigh the costs of buying a used one and ending up with junk again.

 

[AubleAK]

my trans did something similar when i had a bearing come apart. the clutch material plugged the solenoids, which made them code and the metal grinding in the case made my temps skyrocket and impossible to cool. id cut open the pan filter.

 

[durallymax]

When its just clutches I have rebuilt stockers for under $300 in parts . TKT sales is your friend for good new or used stock parts.

 

[dracing70]

When its just clutches I have rebuilt stockers for under $300 in parts . TKT sales is your friend for good new or used stock parts.

yeah i just hate to rebuild it and then it be a solenoid problem or the pump then its smokes the fresh rebuild.

 

[AubleAK]

yeah i just hate to rebuild it and then it be a solenoid problem or the pump then its smokes the fresh rebuild.

you could pressure test the pump and make sure the PSI is in spec

 

[dracing70]

you could pressure test the pump and make sure the PSI is in spec

can the pump be tested out of the tranny? or does it just consist of simply testing the line pressure with a gauge setup?

 

[jc1843]

Be sure you flush the coolers-- including the heat exchanger in the radiator.

 

[dracing70]

ok well i diagnosed this one a bit. started it after setting and all seemed fine. i cleared the codes took it out for a spin and for about 5 seconds it was ok. lol it kicked out of gear and threw a code. 1721 pressure switch stuck off. does anyone think this is as simple as just the pressure switch???? i know she did burn the clutches a bit driving it hot.

 

[AubleAK]

can the pump be tested out of the tranny? or does it just consist of simply testing the line pressure with a gauge setup?

Yes, there's a plug underneath the hell housing you can use.

 

[dracing70]

Yes, there's a plug underneath the hell housing you can use.

whats the pressure usually 220???

 

[AubleAK]

whats the pressure usually 220???

Idk the exact number. But around that area i believe. I could be wrong. Hopefully mike chimes in.

 

[arneson]

For some reason 190s-200 comes to mind. But i could be wrong.

 

[THEFERMANATOR]

For a stock trans line pressure should be around 240-245 above roughly 1500 RPM's, and drop 100 PSI when in lockup. You will need a 10X1.50 o-ring seal adapter to check the pressure. Solenoids can be bench tested with a ohm meter for resistance, and a quick jump with power to check for operation of the actual valve.

 

[dracing70]

For a stock trans line pressure should be around 240-245 above roughly 1500 RPM's, and drop 100 PSI when in lockup. You will need a 10X1.50 o-ring seal adapter to check the pressure. Solenoids can be bench tested with a ohm meter for resistance, and a quick jump with power to check for operation of the actual valve.

Thanks for all the info. The one concern I have are the valve body bores. Iv had one in the past that needed to be reline bored due to some debris going through the bore.

 

[arneson]

240s psi hmmmm. Didnt think it was that high. Couldn't remember tho. Good to know.

 

[AubleAK]

240s psi hmmmm. Didnt think it was that high. Couldn't remember tho. Good to know.

Whats the shift kit bump it up to?

 

[THEFERMANATOR]

Whats the shift kit bump it up to?

Adding in the pressure spring is supposed to get you up to 270, and I believe Mike's spring kit can get you closer to 300. The TRANSGO boost valve can change pressure knock down from 100 to 70 or 50, or you can eliminate pressure knock down and run full line all the time. I think the co-pilot was able to bump it to 300 when it was on, but not sure on that one.

 

[Mike L.]

There is no electronic way to bump pressure up in the Alli over it's 235 psi capability. A .130 shim on the PR spring will bring it up to 255 psi and my spring will bump that up to 290 psi.