95 12V 47RH Has OD but no lockup

WEBERBUILT

WEBERBUILT

Banned
The truck is a 95 with a 47 RH, i've read every diagnosis thread i've come across but none have led me anywhere farther than i've made it on my own.

I just rebuilt the transmission with all OEM parts, with the exception of a billet single disk converter. The transmission shifts fine all the way up into OD but it will never lockup, unless i ground the lockup circuit manually.

It is unknown if the transmission locked up before the rebuild, the truck wasn't even driveable prior to the rebuild and i'm assuming with the amount of damage to the guts of it, it was not locking up before.

When i do that my Solus doesn't show that the converter is locked but it most definitly is locking up when i ground it. The speedo is working and is accurate, i've replaced and adjusted the TPS to the OEM Specs 1v at an idle and 3 WOT.

I've also replaced the PCM but i wasn't able to make sure it worked correctly, it was out of a wrecked truck. The PCM was supposedly out of a 95 as well.

The transmission temperature sensor is working correctly it reads 150-180*.

I've done everything in my mind and plenty of others to try with no luck.

The only thing i can think of is to try another PCM that i know works but that's easier said then done.

Thanks in advance!
 
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Broken wire somewhere? Check the pins at the PCM for damage? Manually grounding it and getting lockup tells me the electronics inside are okay, and that the converter isn't failing. So your good there. Hit up Big Blue24 (will terry) or call up Goerend for some trouble shooting help. Those two sources know their stuff.
 
Well i'm grounding it right at the PCM so the wiring to the trans i would think has to be ok.

I've inspected the PCM connections thoroughly everything is making a connection there.

I'm so tired of looking at this rust bucket!

One issue i'm going to dive into is the throttle won't ever actually achieve 100% on the scan tool, like 80% i believe but i would think it would lock up. It shouldn't have to see 100% to make up it's mind to lock up.

I'll get ahold of Big Blue and i'll try Goerend i've already been in touch with firepunk but they couldn't really point me in any other direction.
 
It won't lock up at that high a percentage until you are moving pretty fast. 70-80ish.
30 percent gets lockup down around the 30 to 50mph range on mine.
 
I'm still going to find out what the deal is with the linkage and correct it. At least we can rule that out though.

I shouldn't even have taken the job the truck has 300k on it and it's been a plow truck for all of it! So you can imagine what kind of pos it is.
 
I've fought this a few times...it's mind blowing how little information is known about the actual operation of these transmissions. Mine (similar symptoms to yours) has bewildered three of the best shops in the country. I'm still stuck in the pattern of 1-2-3-4-4L/U - my switch is the only way to lock it in 2 or 3. I'm willing to live with that, but I understand that some customers aren't.
I'd agree with Hurley on checking the brake switch first, assuming you've triple checked all ground connections. Are you able to manually command lockup via your scanner?


Sent from my iPad
 
Does the overdrive on/off switch work correctly on the dash? Does it light up when you turn overdrive off at the dash switch? When overdrive is turned off, will it lock-up at the top end of 3rd gear like it's supposed to?
 
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