W59 output splines look burned

These are the splines that mate to the transfer case. Why they look hot? Is it useable

 

You look to be having some type of wear. Very hard to determine the type based off one picture but looks to be some type of three body abrasive wear or surface fatigue. The dark marks are most likely varnish. Which is caused by thermal and oxidative degradation of the oil.

What maintenance are you performing and talk about any previous maintenance you performed on the transfer case. Last time you changed oil, what did you use?

 

This is a salvage w59 with transfer case. Unknown miles. From a truck that rusted in half. One dude took the 3rz for a swap in an 80s 4runner and I took the trans/case as I'm mating it to a new 3rz and wanted to have a rebuilt trans. I got the rebuild kit and fsm. I can post other pictures of the shafts but honestly they look REALLY good. I haven't split the transfer case and wasn't planning on it. The seal looks good and the sleeve doesn't have any cracks. Basically I have no idea.

 

most likely oil was never changed and oil degraded and lost its film strength which caused the surface fatigue. Should be fine to continue to use.

 

Thanks.

 

any 'rainbowing' of metal is bc of heat
i see a small amount near the end of shaft...likely (as prev stated) lack of oil/lubrication

weird thing is that the rainbowing is only on the end.....not entire length of spines
i revwd with by boss
i think he nailed it.....
heat was used to remove the input shaft....it was stuck at salv yard

i would re-use all day long
maybe even sand/file the rough areas
GL

 

Interesting though. It IS only on those few splines showed in the photo. There is minimal play on the input and just too be sure I slid a new pilot bearing on and there's no wear there either. It looks all around "low mileage". I'm tempted to just replace the input shaft bearing but am worried I'd put it behind a new engine and start to drive and it screams in 3rd gear or something so now I'm going all the way with it. Does anyone know about selecting snap rings for minimal axial play? Does anyone even sort that out or just reuse the old snap rings? Wonder if there's a kit with the different sizes

 

I wonder if those heat marks come from the factory. Could be a part of the machining process where its heated and the edge of the shaft is rolled for the bevel idk.

 

Man, if you say ‘all the way’
I agree wholeheartedly

But one wrong move/clip/shim missed/misplaced…..

Not saying you can’t tackle
I probably wouldn’t bc of fear of a stupid mistake by myself

The case is out…..I would get some quotes from recommended 4x4 tranny shops. Let experts rebuild or do what you need. Can’t imagine would be more than $500 (with case removed and no catastrophic damage found elsewhere)

 

No one knows how to do ANYTHING where I live. Not a joke. All shops have a horrible reputation. I own a press, gear pullers, indicators, micrometers, etc. I have yet in the 3 year driving restoration of an 01 taco and a 97 4runner (both 3rz w59 4x4s) to take them to a shop for anything other than tires exept one time to get a fuel filter on the 4runnerbc i was lazy and paid for that big time when they broke the knock sensor. Nearly every weekend wrenching on one or the other and driving the dog shit out of them. The tacoma just crossed 300k and had frame replacement just before I bought it, I've rebuilt the suspension etc. The only thing I haven't cracked is the diffs or pulled the heads. Other than that nearly every fastener has been touched by me. I got the fsms and will take my time bc this is a backup drivetrain for when the current one fails so not too big of a rush but when I efff something up or get totally lost I come on tacomaworld.com and usually someone has done exactly what I have and solved it. Can't give up won't give up

 

Yeah maybe. It still has paint on the gear sets to check the setup or something. The receiving splines on transfer case are clean too. Maybe it wasn't burned off on the finish pass on the machine properly

 

You will see the same type of markings on CVs sometimes too. Must be something they do during production

 

I think they use heat when machining splines as I feel like I've seen it on CV axles and other splined stuff. I don't think they'd both machining it off. IMO it's fine. Doesn't look like its damaged at all.

 

If you have probs/concerns rebuilding.....gearcruncher is the one to get a hold of


https://www.tacomaworld.com/members/gearcruncher.90305/

 

Send it.

 

understood.

 

Thanks