What the heck is up with these flanges??? When I removed my front drive shaft, I noticed one of the bolts on the rear (transfer case) side was cock-eyed. I thought it was just loose, but when I began to reinstall it, I noticed the flange actually doesn't line up correctly (no wonder the one bolt was cock-eyed).

I talked to a couple local 4X4 shops that said Toyota had three different yoke/flange combinations and directed me to get a triple-drilled flange from Trail Gear. Can anyone offer an explanation what Toyota was doing here? I have a V6 with an auto trans (A340H). It looked like my trans had been serviced prior to my purchase, but I can't really determine if I have the wrong flange or the wrong drive shaft entirely. The flange on the front of the drive shaft (front diff side) fits just fine. The part number looks to be the same through 1995, so I'm guessing it's the correct shaft, but possible the yoke/flange on the transfer case itself was changed. There is a new shiny gold-colored nut and what looks like fresh white grease around it.

Is it best to use the triple-drilled yoke/flange from Trail Gear? Any other options, short of finding a used transfer case laying around to make a match?

Thanks!

 

They are correct to a point. I think there maybe be even more than 3 from 79-95.
when converting to a new flange keep in mind that you are messing with the pinion bearings, to do it right you actually need a new crush sleeve and need to check bearing preload again to make sure your ring and pinion are still happily married
some get away fine by just counting threads when they remove the pinion nut.

what I am doing on my flange as I ran into a similar issue this weekend swapping thirds is I ordered 10mm drill bits off Amazon and am just rotating the drive shaft 45° and drilling new holes in the flange with it clamped in place. Hope that makes sense

some one may have worked on your rear third. On my stock thirdI am pretty sure the rear d/s had never been removed, the pinion nut was still pretty clean when I pulled it,
was your pinion nut staked (punched to match the notch)? If not that would be a good indicator someone worked on the gears , a lot of shops fail to do thay

 

The OP is talking about the flange on the front of the transfer case, not on the differential, so the pinion bearing is not an issue. You do have to take care not to damage the seal when you pull the flange off. Might be worth just replacing the seal when you do it - new seals are a lot more forgiving than old ones and it's not very expensive.

 

Gotcha, I need a bigger phone..old and blind.
On the T/C the flange is plug and play

 

Pictures would be a big help !!

Is it possible the wrong bolts are installed??

These are special bolts the wrong ones can cause interesting problems

 

Thanks for the replies!! Yeah, I was wondering if I would have to be aware of any bearing pre-load, etc., and the FSM didn't talk about it on the T/C. I'm glad I don't need to worry about that. It still doesn't make sense to me that the center raised ring (on the u-joint flange at the back of the front drive shaft) doesn't allow the flange to sit flush again the T/C yoke flange. The hole pattern is slightly off (I expected that), but the flanges also won't fit flush. If I have the wrong flange on the T/C, should they still fit flush? I may just have to purchase the Trail Gear triple drilled flange and try it. I don't think I'll find component parts for the T/C anywhere.

 

So, funny thing...I was just about to say "screw it" and buy the Trail Gear triple drilled flange, when I was reading on their site that this doesn't work with the chain-driven transfer case. That's what this little T/C is, attached to my A340H transmission. Apparently, mine must have 30 splines and not 27?? So, back to the drawing board. I was thinking I would just turn and drill new 10mm holes in the flange, but the two flanges still don't fit flush. I'm going to have to figure that out first. Perhaps the raised center ring on the flange on the front drive propeller is hitting the pinon nut?

BTW - the pinon nut looks shiny and new (gold color). It also does have the stake in the nut. I would have thought that one this shiny meant it was recently replaced, not "un-adulterated". Interesting thought that it might actually my untouched, rather than recently replaced. I'm going to have to remove the flange on the T/C side to get a better view. The weight of the front propeller is to much to accurately get a good sense why the two flanges don't sit flush.

 

For what it's worth, the nut on my front flange is still shiny after 215,000 miles, so I don't think that's a reliable indicator of new vs. original. I'm taking mine apart again today, so I'll be sure to observe how the flanges fit together.

 

Cool, thanks for that info. Ok, interesting. Now I'm really curious why they don't sit flush. I'm headed off to remove mine now too!

Thanks!

 

Interesting...I just removed the yoke/flange. It actually only has 23 splines. Now, I'm confused. Looks like some of these t-cases have 21 splines, 23 splines (mine), and most have 27 splines. ??

Thoughts?

 

The 21-23 spline difference is refered to where the tranny and t-case join each other, I think all gear drive cases have the same splined outputs. And all chain drive cases have the same splined outputs.

Not sure if the chain type and the gear type splines/flanges are the same though.

I do know that I have an early gear type t-case of unknown year in my possession that was joined to its tranny with a cast iron intermediate housing, and its flanges have smaller diameter holes than the '87 and later cases that I have.

 

Yeah, actually there are at least two splines for the chain-driven cases. Both 21 and 23. Looks like the 23 spline is considered "stronger" than the 21. Common for the V6 trucks and Turbo 4-Cylinder. The more popular gear-driven cases are all 27 spline (this is what Trail Gear makes a triple-drilled flange for).

I was able to sand-down the raised inner rim on the u-joint flange just enough to get it to fit flush on the t-case companion flange (I guess it's called). The holes were off center just a bit, so I decided to drill them out. This is a decent worst-case scenario, until I can find the right flange.

I also learned, while re-installing, that the flange I have on there is certainly not the correct flange, as the previous owner had to pump the whole flange full of RTV because they didn't have the correct seal. They used a big washer to get the correct spacing and then filled the area with RTV. Wow. Funny!

Turns out the shiny-gold pinion nut does reflect a "new" nut after somebody messes with it. They have the wrong flange entirely. Ironically, I'll have to put it back together the way they had it, but at least I have the flanges fitting flush and I can install all the bolts correctly. Once I can find the correct flange, I can correct the whole issue.

 

Ok, I figured it out. There was some confusion on the reverse lookup part number function on ToyoDiy.com. Turns out, almost all the trucks from 86-96 (non-Tacoma) will have the correct T-case flange, IF AND ONLY IF, the vehicle was equipped with an automatic transmission. That is the key. Here is the data from ToyoDiy.com:


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Ok, looks like I can't get the forum to format this correctly, I'll try grabbing a high quality screen shot of the data...

Here it is...