Are these the two speed sensors for the 4L80-E? (4x4) This is the backside of the transfer case.


http://www.dieselplace.com/forum/uploads/BumpinYota/2004-11-01_080747_Speed_Sensor_1_low_res.jpg


Here is the only front sensor I can find on the transfer case, Im assuming it's the other speed sensor?


http://www.dieselplace.com/forum/uploads/BumpinYota/2004-11-01_081021_Speed_Sensor_2_low_res.jpg





Now if they are the speed sensors is there any way to check them for normal operation without just replacing them? Thus far no codes for lack of TCC operation.... Still turning at 2200rpm at 55mph in top gear....

0 out of 10 who saw this didnt know?

Here is that sensor again, this time cleaned up a bit. These are the ONLY two sensors that I can see on the whole damn transfer case..... And there is NOTHING like either of these two anywhere else on the whole damn tranny that I can find....





http://www.dieselplace.com/forum/uploads/BumpinYota/2004-11-01_114509_Speed_Sensor_3_Low_Res.jpg

HELLOOOOOOO??????


Yes I already searched and there is NOTHING to help with identifying parts or on how to check them.........Edited by: Bumpin' Yota

yes those are the speed sensors...as for checking them--i dont know either


If there's no code, then I'd suspect they are working

Thanks for replying man, everyone's description threw me as they all said they looked identicle and a 10mm wrench would take 'em both off. That front one needs like a 20+mm to take it off....lol


It's wierd because for the life of me, I can't detect the torque converter clutch locking in and that is supported by the truck turning 2200rpm @ 55mph.... O/D is definately operational and again stock tires.


I did find a few interesting things on the transfer case, there was a plate with something about a PTO drive on it. And then then there is a secondary pink plate with serial numbers on it.Edited by: Bumpin' Yota

Bumpin'--look again at your trans. Directly above the shift linkage, there should be another sensor just like the one on the transfer case. I'm sorry--they are identicle, and your second/third picture isn't one

I am only seeing a sensor that has a similar plug in, but it held in by a 8mm or smaller nut/bolt of some kind with a sheild. The opening where the harness plugs in faced towards the ground.


When I unplugged the harness, a brownish fluid started to very slowly ooze out.... http://www.dieselplace.com/forum/smileys/smiley5.gif

When I unplugged the harness, a brownish fluid started to very slowly ooze out.... http://www.dieselplace.com/forum/smileys/smiley5.gif





This tells me that fluid is seeping through the sensor--replace it. I had an Oil Pressure Switch that appeared to work, but when I pulled the wiring off, it was full of oil. It's a bad sensor, and gives you a place to start.

This is undoubtedly an unrelated story but I'll tell it anyway. Every GM car I ever had that had a malfunctioning torque converter lockup failed to generate any codes. I know the 4L80E is a sophisticated tranny, run primarily by the PCM but are you sure a failure to lock up SHOULD generate a code?

I thought it would throw a code but I am far from the definitive source on ODBI diagnostic codes...lol Well this sensor does give me a place to start. http://www.dieselplace.com/forum/smileys/smiley4.gif


Ill take some pics for ya to confirm that it's the other speed sensor tomorrow. Thanks for the input guys, I do appreciate it!

t's wierd because for the life of me, I can't detect the torque converter clutch locking in and that is supported by the truck turning 2200rpm @ 55mph.... O/D is definately operational and again stock tires.





When cruising at a steady speed, if you touch the brake pedal just enough to turn the brake lights on, the RPM should jump up a couple hundred. (keep the accelerator steady while doing this)

There should also be a sensor at the tailshaft part of the tranny same side as the one by the linkage. As far as the transfer case DFIK I don't have 4x4 just a 2x4.

The speedo and odometer are correct I just confirmed that this past weekend.


Well the TCC does work after a fashion....


While driving at 40mph I would slightly touch the brake and the TCC would unlock making the rpm jump by about 450 rpm. Then while driving at 70 mph I would again, slightly touch the brake and again the TCC would unlock, HOWEVER the rpm only jumps up about 100 rpm.


Is that normal?Edited by: Bumpin' Yota

Tranny slip varies according to line pressure and throttle. The tcc allows more slip at the mid- rpm range and then locks around 2000 rpm to reduce slippage. throttle it lightly and it will hardly slip, throttle hard and it slips 300-400 rpm.

so you are saying that that is normal then right?


at 70mph im turning at 2800 rpm, so im really thinking I have 4.56 gears despite what the pro codes say....

That rpm seems high for stock tires and 4.10 gears. I run larger tires 33x12.5x16.5 with 4.10gears my rpm 2250 at 70 mph. 2050 rpm at 60 mph with the tcc engaged.


I had an incident where my tcc didn't engage all the way home 70 miles or so. my rpm was 2400 at 65 mph and I had a code for the TCC. It never came back or acted up again.Edited by: quantum mechanic

I only have 16" tires and I run nowhere near 2800 at 70mph with 4.10's

so you are saying that that is normal then right?


at 70mph im turning at 2800 rpm, so im really thinking I have 4.56 gears despite what the pro codes say....





What size tires are you running? Any chance the spedometer is off a little

Are you running an alternator with an incorrect sized pulley?

the question on tire size has nothing to do with the rim size but the tire size ie... 245/75/16 or 285/70/16. the overall tire size can be a big factor, or someone changd his gears onr night.

Just to help with your guys reference i'm running 4:10's also, 16 x 265's tires, 70 Mph @ 2500 rpm.


One other thing, no one addressed my question in another thread, my brake peddle has no effect on lock-up, only backing off the throttle and getting into it again will it unlock and lockup again? I'm guessing that was something that changed after my 95 as this is a 2000. Anyone really know?

My guess is the change in technology between '95 OBDI and '00 OBDII. The OBDII ECM has more than twice the memory at 32bit vs 16bit OBDI iirc and the internal speed is quicker OBDII. The ECM has more room for programming and memory and Perhaps it's flashed to act as it does. The reflash get's you past all that.

Just my 2 cents , at 110km's 0r 68-69 m I'm running 25-6 rpm's with 410 's and stock tires 225 -75 - 16 . Always thought my rpm's were high but maybe not .( 5 speed ) Alan

I need to change the RPM levels - 70mph has me at 2650 rpm not 2800.


as far as tire sizes I think if we keep this truck long enough it will be adorned with some 245/85r16s soon...


225/75r16 - 29.3" tall by 8.9" wide


245/75r16 - 30.5" tall by 9.6" wide


245/85r16 - 32.4" tall by 9.6" wide


285/70r16 - 31.7" tall by 11.2" wide


This is a dually, so there is no way I could ever fit the 285s but I might be able to fit the 245s....


As far as the alternator pulley being the correct size, I think it is but am unsure. The alt has been replaced 2x now with a carquest remanufactured unit...Edited by: Bumpin' Yota