Probably a grenaded transfer case

[DouglasVB]

If memory serves his 4Runner also has had issues with rear axle bearings, both driveshafts and the steering box. It's not a knock just that I get the sense he's hard on the truck and might benefit from Dana 60s and an Orion.

I'm flattered you think I wheel hard but I really don't

My suspicion is someone before me wheeled the out of the truck and I'm still paying the price. I also wonder if my rear axle housing is bent and I'm pretty sure my frame isn't straight.

I chatted with Ian at Wheel Every Weekend yesterday about ballpark prices for building a 1st gen taco. Would be on 40" tires, F350 axles, use a divorced Atlas T-case (because he would start with a 2WD truck which saves a lot of cost on the base truck), full roll cage, 3 link front, harness seats, etc. It was actually much more reasonable than I expected and has definitely given me and my something to think about. I don't think Ian would want me throwing numbers around openly so I won't post the price here. The biggest potential problem I see there is I want a manual, the 1st gens only came with standard or access cab options for the manual, and if we decide to have kids in the next year or two it would be better if whatever I end up with has four doors. I would be the most envied and most hated dad dropping the kids off at school in a monster truck like what Ian proposed For sure I'd need one of these bumper stickers:

 

[DaveInDenver]

I'm flattered you think I wheel hard but I really don't

OK, but then why...

Would be on 40" tires, F350 axles, use a divorced Atlas T-case (because he would start with a 2WD truck which saves a lot of cost on the base truck), full roll cage, 3 link front, harness seats, etc.

 

[DouglasVB]

OK, but then why...

Because reasons?

I am falling into the same trap that every weekend warrior falls into. I want the ability to do something crazy but 99.9% of the time I'll never use it.

I should just get a Ford Maverick and be happy flexing in the Home Depot parking lot.

 

[DaveInDenver]

Because reasons?

I am falling into the same trap that every weekend warrior falls into. I want the ability to do something crazy but 99.9% of the time I'll never use it.

I should just get a Ford Maverick and be happy flexing in the Home Depot parking lot.

It's your money, it should make you happy above all.

 

[DouglasVB]

It's your money, it should make you happy above all.

And that's the hardest part of it all to figure out

 

[DaveInDenver]

And that's the hardest part of it all to figure out

Since I have no money for such extravagances I believe I'll mull it over riding Kokopelli this morning. Over and out.

 

[DouglasVB]

Finally got up the energy today with the new Juneteenth federal holiday to take apart the rear axle (mostly). On one side the inner axle shaft seal had failed so the axle grease was soupy with a little sliver glint. On the other side it was still in really good shape. No immediately obvious issues on either side aside from the silver glint to the soupy grease on the passenger side.

I'll put some new seals on (I even have a couple spare Marlin Crawler inner axle eco seals ready to go!), repack the grease, and reassemble the axle ends tomorrow so I can set it back on tires rather than jack stands. I'll also remove the differential and inspect it.

I think I might go ahead throw some new bearings in on the side that had the blown seal. I've got a brand new spare set and a spare used set. If I do decide to replace, then I'll put the old ones into my spares box for a trail repair.

Tomorrow I'll use my angleometer to make sure there isn't some misalignment issue with the pinion flange and the output shaft.

I will also remove the diff tomorrow (didn't have my drain plug Allen wrench with me today) and inspect it thoroughly. Hopefully it's all normal and not a horror show.

The splines on the outer ends of the axle half shafts are a bit worn. Nothing terrible yet but it's noticeable. These half shafts have maybe 15k miles (probably more like 10k) on them and came from FROR brand new about four years ago. I'm using Diamond Axle hubs. Of course I didn't get a photo of the splines today. I might bring over my old axle half shafts tomorrow to see how they compare. The old half shafts and some FJ80 hubs failed on me about four years ago just driving on a paved back road. The FJ80 hub stripped out and allowed the half shaft to spin without engaging the wheel. That was not a fun situation at the time.

 

[Notyourmomslx450]

Definitely do rear bearings. The only reason the seal ever goes out on a rear axle is because the bearing is bad

 

[DouglasVB]

Here is what the two half shaft splines look like. Inner splines look brand new but the outers look like this.

Now onward to removing the diff!

Edit.....

And check out the wear on the diamond axle hubs. These were new in 2017.

 

[ScaldedDog]

Douglas, a JK or JL jeep may serve you well, as would a new Bronco, if you could find one for anywhere near MSRP. The Chrysler motors aren't great, but the issues are well known, and not hideously expensive to fix. Wheeling with 35s will bend the cardboard rear axle flanges, but that's a really easy fix, and 35s only require a 2.5" lift, or trimmed fenders.

What I suspect you really want, as did I, is a 2014 '85 4Runner. That's just not a thing.

Mark

 

[DouglasVB]

Today I put back together the rear axle hubs. New bearings in the side with the blown inner axle seal. Rotated the tires. Popped the diff out. The diff looks immaculate. @jps8460 did an outstanding job when he built this diff for me. Seriously. It's so beautiful I just looked at it for a good five minutes.

The gear oil was a bit yucky from the bearing grease that managed to get in. But there was no metal.

The outer splines on the axle half shafts and the diamond hubs do concern me a bit. It's looking similar to when I had the 80 series hubs and the previous half shafts on about four years ago when I had one fail. I'm not sure why they're doing this and I am very positive I've got less than 10k miles on these. So my guess is it's something to do with my driving?

I took some angle measurements on the pinion flange, the drive shaft, and the output flange. The pinion flange is about 72 degrees. The driveshaft is about 19 (or 71) degrees. The output flange is about 86 degrees. I've got a double cardan joint. So I think the pinion flange and driveshaft add up to about 91 degrees.

So the angle difference between the pinion flange and the driveshaft is about 1 degree or a little less. At least I think that's how I'm supposed to interpret it from http://www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml#Double-Cardan-Measurements So then if I take the average of the two flanges and the difference between that and the driveshaft, it's 8 degrees.

So I think this means I need to do something to change the angle of the dangle? And I'm thinking I need to do that with some shims to put between the axle and the springs? Maybe this is the source of all the problems I've had over the years?

Anyway here are some photos of the beautiful diff:

 

[DouglasVB]

Talked with Brian at FROR about my outer axle half shaft splines. The issue is I didn't grease them properly which can cause fretting. Lesson learned! I had no idea they were supposed to be greased.

He thought I could probably keep running them maybe forever if I grease them well but if it were on his truck he'd likely replace them. There is one half shaft that's worse than the other and the old half shafts were the same so I might pull the worse one and put in the better old one, and run it for now.

I'll be putting the diff back in and buttoning up the rear axle later today so that I can do a test drive and see what happens.

 

[DouglasVB]

Got everything back together today. I was too tired to take it on a test drive so I'll let the sealant set and do a test drive tomorrow. No issues putting everything back together.

I went ahead and pulled the drive shaft all the way off to get better flange angle measurements. The measurements are:

Output shaft flange: 88.0 degrees
Pinion flange: 74.1 degrees
Driveshaft: 17.4 degrees

Per Roger Brown's calculation method, I believe I'm about 1.5 degrees out on the measurement between the pinion flange and the driveshaft. I *think* that's close enough to in spec considering the truck is empty currently that I'm good there. Otherwise I'd need a 1 degree shim.

Does that seem right? Am I thinking about these driveshaft angles correctly or am I missing something?

 

[rover67]

Got everything back together today. I was too tired to take it on a test drive so I'll let the sealant set and do a test drive tomorrow. No issues putting everything back together.

I went ahead and pulled the drive shaft all the way off to get better flange angle measurements. The measurements are:

Output shaft flange: 88.0 degrees
Pinion flange: 74.1 degrees
Driveshaft: 17.4 degrees

Per Roger Brown's calculation method, I believe I'm about 1.5 degrees out on the measurement between the pinion flange and the driveshaft. I *think* that's close enough to in spec considering the truck is empty currently that I'm good there. Otherwise I'd need a 1 degree shim.

Does that seem right? Am I thinking about these driveshaft angles correctly or am I missing something?

The t case output flange and pinion flange should be basically parallel…or close to that but rather with the pinion flange maybe biased up a few degrees. This allows the flanges to be parallel under acceleration. Your numbers make it look like they are not parallel.

 

[DouglasVB]

The t case output flange and pinion flange should be basically parallel…or close to that but rather with the pinion flange maybe biased up a few degrees. This allows the flanges to be parallel under acceleration. Your numbers make it look like they are not parallel.

I've got a double cardan joint rear drive shaft. Not sure if that makes a difference but I think it might? I don't see how I could make the two flanges parallel and also keep the u joint at the back of the drive shaft roughly parallel.

 

[ScaldedDog]

Douglas, you just want the pinion to point at the flange of the DC joint, or slightly below, as the pinion will come up slightly under acceleration.

Mark

 

[rover67]

Ohhhh, I did not realize that. yep, what Mark said.

 

[DouglasVB]

Douglas, you just want the pinion to point at the flange of the DC joint, or slightly below, as the pinion will come up slightly under acceleration.

Mark

Okay that makes sense. That's what mine is setup like. Kinda hard to make out in the below photo but the pinion flange is tipped up to point toward the output shaft flange.

 

[DouglasVB]

Success!

I took the truck on a test drive today and went all the way up to 75 mph with no problems. It was nice and smooth at any speed. Well... as nice and smooth as a truck like that can be.

I'm still a little confused by what the root cause was though. Maybe that side with the soupy grease was starting to go out and caused the vibrations? Maybe rotating the tires is masking a tire that's unbalanced? Maybe the truck needed a time-out for a while?

Anyway now I can think about going back and finally fixing the A/C that's been broken since long before I had the truck. And a laundry list of other comfort and convenience tasks.

 

[FJCDan]

Great job Douglas.