What is the largest tire 8" to 9.25" axles can handle?

[meigsrock]

What is the largest tire 8" to 9.5" axles can handle?

Suppose some day I upgrade my DD 92 pickup into a SAS big tire 4x4. What is the largest tires I could expect to run with the following parts before the tire size just starts busting axle parts up:

22re
double t-case
FJ60 9.5" front axle w/ lsd or locker
8" rear axle w/e-locker
axles will be trussed, ball ends trussed
5.29 gears
probably leaf springs all around

Alaska 4x4 driving = trails, mud, river crossings, probably not much rock.

Consider this a buggy so disregard any tire clearance issues.

I am looking for suggestions on tires size with stock axle components, and tire size with modified axle components like long-fields etc.

(I see a lot of folks with 8" front and 8"rear axles running 36"-38", maybe even occasional 40's?)
Thoughts, experience, opinions? Thanks.

 

[GRM]

Elockers are weaker than v6 diffs. IMHO 35 max. I've seen plenty break with 33's, and have broken mine on 35s

 

[meigsrock]

I thought the e-lockers were v-6 diffs as they were only offered in the Tacoma v-6 TRD packages / four runners. I found one for sale but if it is a big weak link then maybe I would be better off going with a Tacoma 8.4" with an ARB or other type of strong locker that can handle larger tires.

 

[KLF]

Yah, I don't see how a TRD e-locker can be "weaker" than a V6 diff. The pinions and gears are the same, carrier pretty much as well. Same bearings except for one carrier bearing on the locking cog side is much bigger. Maybe the housing?

 

[GRM]

My experience is that the e-locker case deflects much more than the standard v6 case. Every one I have removed (from a wheeling rig) has a weird, deep gear pattern from high torque loads.

Here is my experience:

79-95 Axles are good, housing is strong, and typically hold up to 37" tires in everything short of a rock-buggy.

96+ axles. Elockers deflect alot, break around 33" tires, the 8.4 is very good up to 40" tires. Standard 8" (non-elocker) is good to 37's. Housings are weak (bend), and the shafts are weak (bend at the flange).


I'd love a good, cheap solution, but I'm going to swap my 8" elocker rear axle for a diamond housing, 9.5" land cruiser (fzj80) elocker, full float with disk brakes. Yes, its a $2500 axle, but its one less thing I worry about on my truck.

 

[meigsrock]

I found a Tacoma 8.4" axle for a good price so looks like I won't buy an e-locker and will go with the 8.4" rear axle instead as they are a lot stronger and the width will match my 60" FJ60 front axle. I just have to take a weekend to go get the thing.

Otherwise I will make my own axle by combining my fj60 rear and a 92 pickup 8" axle. I read an article somewhere on how to do this....toyota trails maybe. He used the center fj60 housing a few inches of the fj60 axle tube housing and the land-cruiser third member for the center section. For the ends he used some of the pickup housings out to the flanges, and used the pickup inner axles, breaks. They are both 30 spline so they convert right over. It turns out that the OD of the pickup axle just fits inside the ID of the FJ60 axle. So combining the two you get a centered 9.5" third member with pickup axle shafts/bearings/ends/and breaks, eliminating the C clip from the axle in the process which people seem to think is a better.

I will look into this some more if I go this route for sure as I already have both the axles to make this happen. I guess if it does not see much road use I might look into running the stock offset fj60 axle if it won't cause any problems. Not sure on that however.

I would love a diamond full floater too but way out my budget at the moment.

It may take me a while to get it all together but it looks like 5.29's are a good match for 36-37" tires with the 22re. If I can get a duel t-case or engine swap then I would consider 38-40's.

 

[GRM]

I found a Tacoma 8.4" axle for a good price so looks like I won't buy an e-locker and will go with the 8.4" rear axle instead as they are a lot stronger and the width will match my 60" FJ60 front axle. I just have to take a weekend to go get the thing.

Otherwise I will make my own axle by combining my fj60 rear and a 92 pickup 8" axle. I read an article somewhere on how to do this....toyota trails maybe. He used the center fj60 housing a few inches of the fj60 axle tube housing and the land-cruiser third member for the center section. For the ends he used some of the pickup housings out to the flanges, and used the pickup inner axles, breaks. They are both 30 spline so they convert right over. It turns out that the OD of the pickup axle just fits inside the ID of the FJ60 axle. So combining the two you get a centered 9.5" third member with pickup axle shafts/bearings/ends/and breaks, eliminating the C clip from the axle in the process which people seem to think is a better.

I will look into this some more if I go this route for sure as I already have both the axles to make this happen. I guess if it does not see much road use I might look into running the stock offset fj60 axle if it won't cause any problems. Not sure on that however.

I would love a diamond full floater too but way out my budget at the moment.

It may take me a while to get it all together but it looks like 5.29's are a good match for 36-37" tires with the 22re. If I can get a duel t-case or engine swap then I would consider 38-40's.

Few points:

1) your Fj60 front axle is 58" wide. If you install IFS toyota hubs (like those on the front of your '91 pickup) it will make the axle 61" wide.

2) Are you talking about this hybrid axle for the rear instead of the 8.4" you just purchased? FJ40/minitruck hybrid rear axle- Land Cruiser Tech from IH8MUD.com While it looks good on paper, you really should be used on a trail rig. In order to drive an axle like this on the highway, an alignment jig is needed to weld it together (aprox $500-600 tool), otherwise you risk having a bent axle from welding and tube alignment. Result: quickly worn bearings, worn tires, and alignment issues.

Also: watch out on the 8.4 rear. While the 3rd is very strong, the axle housings & axle shafts are prone to bending at the flange.

 

[meigsrock]

1. All my searching cam up with FJ60 are 60"front/ 57" rear. I guess I need to re-measure when I get home. The 96-04 Tacoma axles are 58-60" depending on year. Newer Tacomas are 64", too wide.

2. Haven't purchased the 8.4 yet but will as soon as I can. It is about a 4 hour drive one way to get it.

That is the link for the build on the hybrid axle I saw. Thanks for the link. I think if I did that axle mod it would be a trail truck. I can weld, fab some stuff, and reinforce things, but you are right about getting everything exact. Probably better to see how much a diamond housing for the same components would be and start saving.

I have a couple of projects in the works.

1. A camper 4x4 conversion with a fj60 axle up front and right now a ifs 8" in the rear. It may stay 8" or it may go 8.4", have not decided yet. A Toyota one tone full floater would be best if I can find one. 29-33" tires on that one, have not decided yet, Still in the works.

I am also pondering going sas on my 92 pickup with the 36-38's in a year or two, which is where this discussion mostly takes place. I have another set of FJ60 axles, and so far the camper swap is good so I would use another FJ60 axle up front and need something a little stronger in the rear to match. It would be nice to have the same R&P size in the pickup so I could carry one spaire third member if I needed that would fit both ends, but not a total must I guess.

I will reinforce the 8.4" axle with gussets along the top when I get it. The pickup 4x4 guys up here have had really good success with the 8.4 holding together under big tires so it is good to know it is a good option.

Going to go look up diamond axle housings now.......