Hopefully someone can answer my question since I don't know sh!t about transmissions. I got my swap done into my 84 GMC 4x4 and have been driving it none-stop since Saturday. Runs like a champ! Only problem is, it shifts really hard and it won't go into overdrive. Could it be the fact that I'm not using the original transfer case and it thinks its a 2wd?
A drunk mans words are a sober mans thoughts
1984 GMC Sierra Classic 3/4 ton 4x4
Dropped in 6.0L LQ4 and 4L80E transmission out of a 2000 Chevy Silverado 2500 HD
Do you have both speed sensors connected on the driver side of the transmission?
See my truck data in the "My Garage" section here... http://www.ls1truck.com/forums/my-ga...tml#post191709
Yeah they're both there. The rear one is brand new since originally it was just a plug.
A drunk mans words are a sober mans thoughts
1984 GMC Sierra Classic 3/4 ton 4x4
Dropped in 6.0L LQ4 and 4L80E transmission out of a 2000 Chevy Silverado 2500 HD
is there a pulse counter wheel thing in the transmission? Some transmissions didn't have two pickup points in the 80e, one was blocked off and the reluctor wheel thing isnt there.
See my truck data in the "My Garage" section here... http://www.ls1truck.com/forums/my-ga...tml#post191709
Yeah the reluctor ring is definitely there. I know its all there because I felt really stupid when I swore up and down that it was a sensor and it turned out to be just a plug. Before I found that out, it wouldn't shift past second gear.
A drunk mans words are a sober mans thoughts
1984 GMC Sierra Classic 3/4 ton 4x4
Dropped in 6.0L LQ4 and 4L80E transmission out of a 2000 Chevy Silverado 2500 HD
It may be your TP sensor? Mine did that and shifted really hard into 2nd and 3rd. The TP sensor was off, but I have a drive by cable.
Jamest
12 Sec. Club! SOLD
La Viuda negra/ a.k.a. Black Betty
LQ4 6.0L, WCCH HEADS, LEVEL 5 FLT 4L80E TRANS. WITH TRANS BREAK, YANK 3200 STALL, TRICK TURBO, TURBONETICS T-76 TURBO, CUSTOM INTERCOOLED, 68lb INJECTORS, CUSTOM S/D TUNE FROM NELSON PERFORMANCE, COMP CAM 212/214 .557/.559 116+2, SNOW METH. KIT, . ALL INSTALLED AND DYNOED AT NELSON PERFORMANCE: 5**?HP @ 5073rpms and 5**TQ @ 4389rpms AT THE WHEELS WITH 10 PSI OF BOOST. ALL 3/4 TON TRUCK 5435LBS, NOTHING TAKEN OFF, STREET TIRES, AND USUALLY 2 BABY SEATS. WANNA RIDE?
SOLD***
Tow/Haul switch is wires directly to the 2000 BCM. The BCM sends a Class2 message to the PCM to engage T/H mode. I don't think you have that issue but I'm not sure how some of these swaps work without the use of a BCM.
I also originally missed the fact you have no VSS in the transfer case. Yes, you need it...badly. It makes no real difference if the T/C is in 4WD or not AS LONG AS IT'S NOT IN 4LO. I doubt a 4L80 will shift into OD in 4LO. Also, I'm surprised it shifts at all with no VSS. It's my understanding that the two speed sensors on an 80 are for internal trans slip diagnosis and TCC application. The VSS does all the work for shift timing/pattern, etc.
Here's the GM internal component checks for no 4th gear.
Seals (527) (531) Nicked or cut
Cup Plug (530) Missing
Bolt (26) Loose, broken, or missing
Piston (528) Jammed
Spring Assembly (532) Jammed
Retainer Ring (523) Not seated
Friction Plates (525) Worn or burned
Reaction Plates (526) Worn splices
Housing (529) Damaged or cracked
Housing (504) Broken
Reaction Plates (508) Worn splines
Sun Gear (650) Worn
1-2 Solenoid (313)
• Stuck Off
• Pinched wire
• O-ring failure
• No voltage to the solenoid
No signal to the solenoid
3-4 Shift Valve (308) Stuck
PCM Quad Driver Module Failed
Check the PCM for current DTCs.
Since he has both speed sensors in the trans, shouldnt he be able to run a 2wd PCM and it should shift the transmission perfect regardless of transfer case gearing? Isn't the reluctor wheel on a transfer case shaft 40 pulse, too? Putting the sensor in the transmission should have alleviated the transfer case issue, unless there isnt the reluctor plate in the 80e transmissions that are built for 4wd trucks, correct?
See my truck data in the "My Garage" section here... http://www.ls1truck.com/forums/my-ga...tml#post191709
I see...yes, I guess that makes sense with 2WD tune....unless the pulse count is different.
Posting Permissions
Reply With Quote