Topic: new W56 transmission - noise in 5th, no speedo/odo

[tullamore]

Greetings! This is my first (but likely not last!) post on this forum.

I have a 93 toyota pickup 4x4 with a 22re, 171k. The clutch went out so I decided to replace some major driveline components while the everything was pulled out. I had a new tranny (W56) and transfer case (rebuilt units from ManTrans, mistake?) put in, in addition to a new clutch from Marlin.

First thing I noticed when I got the truck back from the shop was that my speedo and odo had stopped working. The mechanic said he didn't know why that was happening because he hooked it all up properly. It's been a while since I've messed with a transmission, but I'm honestly not sure how you could screw up hooking up the speedo. It's one cable you just plug in. So, immediately I'm suspect of this transmission.

Then, a few days later, I finally got her out on the highway and engaged 5th gear for the first time on this new transmission. I'm greeted by a distinct grinding/hissing sound only in 5th gear. The sound is really only there when you're giving it gas. If you disengage the clutch, it goes away. If you let up on the gas it goes away.

Additionally, there is a very high pitched, constant ringing/squeal that seems to be coming from somewhere near the rear of the truck. It is constant and not tied to engine speed or actual mph. It is present only when rolling, but goes away at very low speed (less than 5mph). This has been present since I bought it and was not resolved with the new driveline parts. I thought I would include that info here in case it plays into the diagnosis. Sorry for the barrage of information, but I figured too much is better than not enough.

So, here I am. New transmission, new noises and new issues. I'm going to have to take it back to the shop to have them take a look/listen, but any input from the forum would be appreciated. Could the 5th gear noise be something besides the transmission? Rear diff perhaps/ related to the ringing sound? Could the broken speedo be something else? Broken sensor? I need to try to rule out everything before I have them pull the transmission and send it back to the rebuilders.
Thanks in advance,

T

[hamish_18]

Well. if you look at your transfer case, on the passenger side. There will be either a cable, or a black 3 wire sensor plug at the end just before the output shaft. This is either your speedo cable(going to your speedo which has the vehicle speed sensore), or your vehicle speed sensor. If your speedo stopped working, I would say either he didn't plug it back in all the way, or he didn't screw the cable back to the speedo gear correctly. If you are hearing a whining sound then perhaps that gear is not lined up with the gear on the output shaft.

Or at the worst, they didn't put the little ball that acts as the key for the speedo gear on the output shaft, and the shaft is spinning in the gear.

[hamish_18]

Looking at my wiring diagrams, on your 93, the combination meter(gauge cluster) shows that your truck has the 3 wire Vehicle speed sensor wires coming from the external sensor. So you should see the black plug with three wires coming from the end of your TC. I would unplug it, and pull the bolt off that holds the sensor in. Check to make sure that the nylon gear is intact. If you can, which I am not sure. try to stick your finger in the hole, and see if you can spin the gear that is on the output shaft. If you can that is bad. If you can't then it's something else whining in your tranny/TC.

Hope this helps ya

[tullamore [OP]]

Thanks hamish, I'll get under there and check out the speedo sensor to see if I can tell whats going on. I didnt even know it hooked up to the t-case. That rules out the transmission for why the speedo isnt working. If anything I can have the guys at the shop double check that is was hooked up properly. You mentioned that its possible "they didn't put the little ball that acts as the key for the speedo gear on the output shaft, and the shaft is spinning in the gear." Can you elaborate on this?

The speedo not working is the least of my worries and probably not related to the noises. So now, anyone have any ideas on these gremilns?

There are two separate noises that I'm trying to figure out.

- 5th gear hissing

- rear end ringing/ very high pitch noise (almost like when you walk into a room with TV on, but lower)

[hamish_18]

well the reason why I spoke about the ball on the shaft, is if that shaft is spinning freely inside the worm gear, then it could sound like a bad bushing as the tollerance on the gear to the shaft is not that tight. Hence why the ball is used. Are you sure you're hearing it in only 5th gear? Is it that you're hearing it at a certain speed? So what happens if you get up to highway speeds(unless you don't think it's a good idea because of the sounds you're hearing) and put the tranny in neutral. Do you still hear the whine?

I would make sure there is proper fluid in the TC and tranny too. I hope they didn't forget to fill it all up.

[tullamore [OP]]

Speedo problem solved (I think), thanks to your advice, hamish.

I took a quick look under by the t-case, and sure enough the little black plug that goes into the sensor had a bad wire. I'm going to take a wild guess and say that once I get that spliced back together it will solve the speedo/odo issue.

As far as the noises go, here is what I can tell you. I'm certain they filled up both the tranny and transfer case, though I am not certain they used the right weight of fluid.

5th gear noise - I tried to replicate it in other gears but its clearly only in 5th, regardless of speed. It goes away when you put the tranny in neutral at speed and subsides when you let off the gas at speed. It is most noticeable when cruising in 5th and giving it a little gas. It's less noticeable at open throttle because of engine noise. It is constant and the tone of the noise does not seem to be tied to engine speed or cruising speed.  The best way I can describe it is a midrange-y hiss that sounds kind of like muffled static. It's not the kind of "oh " noise that would cause you to immediately pull over and stop driving, but it is definitely not normal and has appeared only recently with this new transmission.

The other noise I have had for some time now. It is clearly audible from the outside of the truck or with the windows down, and is especially noticeable when coasting at less than 30 mph through neighborhoods or cruising in traffic (the sound reflects off of other cars so it is easier to hear). It is always there regardless of the gear or clutch engagement. As long as I am moving faster than around 5 mph, it's there. It's tone is constant and does not rise or fall. The best way I can describe this is a very high pitched constant ringing or squealing.

[hamish_18]

hmm well that is half good news then!

So it doesn't sound like straight cut gears(ie what reverse sounds like). Dude I don't know. What work did they do in the new tranny? just put new bearings in? did they have to replace any gears out? We've reached the end of what I know so, hopefully marlin will chime in.

Sorry I couldn't be of any more help

[tullamore [OP]]

No worries, ham. You've been a huge help already. 

The tranny and t-case are rebuilt units from a transmission rebuilder. It's the equivalent of a brand new unit. It should be flawless as far as I'm concerned, especially considering that the 5th gear noise did not exist before the new transmission went in.

I think I have a hunch on the high pitched noise that I've had for a while. (just to reiterate, this is separate from the 5th gear noise just appeared with the new driveline components) I can hear it while coasting with the engine off, even at low speed. It was suggested to me that it could be the brakes - a piston rubbing on a rotor. I'm going to take a look into that.

The noise that concerns me most is this 5th gear noise. I'm thinking it's going to require pulling the new tranny and sending it back to the rebuilder, but I want to be as certain as I can before I do it.

[hamish_18]

well good luck!!

[J-bone]

i have the same issue with my trans that i put in my truck. 1st-4th sound fairly good but as soon as i put it into 5th i get this hissing/grinding noise. if you find out any info on this please post.