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View Full Version : How far back should I move my axle?


nakman
06-15-2009, 09:45 PM
My back tires rub when the tire stuffs. I still need to clearance the bottom of the flares, but it's hitting pretty much the whole inner fender well, makes a horrendous noise particularly when it's really stuffed in there :D

According to world renown expedition expert, great guy, and family friend Scott Brady, I need to create a "lift block" that repositions my axle. His site says...

For rear tire fitment the most critical adjustment is to center the axle in the wheelwell. This can be accomplished by replacing the springs with an engineered solution like Deaver, or use a .5" lift block with repositioned pin location.
After centering the axle, the fenders need to be trimmed along the wear marks and the hex bolts replaced with the fender washers and screws.
The tires still rub slightly under full compression, but have not caused any damage.
http://www.expeditionswest.com/equipment/tacoma/bfg_mt_km.html


So my lift block will have a hole in it that allows the spring pin to rest inside, then it will have a pin that will poke down into the spring perch, and the distance between the hole and the pin is how far my axle moves. Simple enough, right? here's a drawing of the lift block:

nakman
06-15-2009, 09:47 PM
So the question is, what should that distance be? I'm thinking .750", which is what I drew above. here's a picture:

Hulk
06-16-2009, 12:56 AM
All the way behind the bumper. Just think of the trails you can do with a super long wheel base, brutha!

DaveInDenver
06-16-2009, 05:48 AM
You're starting down the mini truck path, so get to know our tools and techniques.


Do nothing. It'll self clearance.
Do a little more. Go 'wheeling and use hammer (I prefer the 3 lb Eastwing drilling hammer, YMMV) to smash sheet metal that has rubber on it
13260
Be preventative. Use Sawz-All to make wheel wells bigger.
13259




Or I suppose you could be all nerdy and do it your way. Incidentally, if you look at the front edges of my back wheel wells, they are clearanced using method #1 with a little of #2. My front fenders are clearanced using method #2 just about exclusively.

DaveInDenver
06-16-2009, 05:53 AM
Just to show the way it happens, the rears getting some additional clearance put into them. In my case the wheels are close to the rear lip and so either the front or the rear needed a little more space. So yeah, totally ghetto, but I let the tires tell me where I needed to cut and bend... BTW, the plastic flare (on mine it was just a little plastic rock guard) can be removed and that'll give you a bit more space, too.

http://www.armbrusterweb.com/tripsfolder/longtripsfolder/rubithon08folder/files/page75_10.jpg

nakman
06-16-2009, 08:05 AM
I already did #2 Dave to my front wheel wells, I cut the inner fender then mashed over a pinch weld, so no more rubbing there. I can nick the front bumper occasionally, but I'm not going to worry about that one as I'll eventually get a different front bumper.

Matt this long wheelbase is noticeable- feels like a school bus when going around switchbacks, and pretty humbling when you know the 80 would have done it in one shot, and you're backing up for another line. But you do have a good idea, if only I had a parts 80 sitting outside with some free full floaters... :)

Jacket
06-16-2009, 08:38 AM
I've been running the self-clearancing method for some time, but eventually you end up mutilating your expensive tires (if sheet metal is involved)...

http://www.risingsun4x4club.org/uploads/Jacket/hc3.jpg

I have the same problem as you Tim, and it's worse on the driver's side for me. I think if I had an extra 1/4" to 1/2" clearance toward the back of the truck I'd be fine. Does someone make those plates for re-centering the spring pin?

Another option would be extending your bumpstops a bit to keep the tire out of the fender.

nakman
06-16-2009, 08:50 AM
I have the same problem as you Tim, and it's worse on the driver's side for me. I think if I had an extra 1/4" to 1/2" clearance toward the back of the truck I'd be fine. Does someone make those plates for re-centering the spring pin?

Another option would be extending your bumpstops a bit to keep the tire out of the fender.

You bloddy gol dang right someone makes those... do you know the OD of the spring pin off-hand? That's the only dimension that's holding us up from producing these, just need to know what size hole to put in there, and what size pin. But you're in for a set! :thumb:

Caribou Sandstorm
06-16-2009, 09:02 AM
Hey Tim,

How are you liking those tires?

Air Randy
06-16-2009, 09:04 AM
I used option #3 to fix mine.........

And yes, 4+ sells those relocation plates pre-made. I'm not sure if they come in different sizes though.

nakman
06-16-2009, 11:09 AM
I have never had good luck searching for anything on MAF's site.. today was no different. But it turns out folks do already make these, thanks for the tip!

Allpro has them http://www.allprooffroad.com/pickupsuspension/51

So now I need to decide if I just buy these, or still fab my own... at least I was right about the 3/4" :)


Chris, tires are working well- they're pretty quiet on the pavement, and I've had them up to about 75-80 with no shaking. Off road they appear to have done the trick, but I haven't done anything with them yet that any AT couldn't have done. I did get "first tracks" across a snow drift and they did alright, but I also had one tire on dirt the whole time and a locked axle. Let me know if you want to try them out some time, can you put 16" 80 rims on an FJ? You can put them on your 80 if not.

Jacket
06-16-2009, 11:50 AM
I've been postponing dealing with mine because I've always intended to replace my AAL with a new spring pack, after which I'll deal with what I'm left with. But that would require me to figure out my long term solution for the bed canopy, storage, etc. :blah:

PS - looks like there's quite a few choices already out there. All Pro, Sky Manufacturing, Roadless Gear and 4crawler all produce a relocation plate. But of course I'd buy one of yours if you made one. :beer:

nakman
06-18-2009, 04:10 PM
Ok Matt you're on, I've got a set for you. And these are special, made from 6061 T6 aluminum, and 303 stainless pins, guaranteed never to rust, or stick to magnets for that matter. :D

DaveInDenver
06-18-2009, 04:19 PM
I was secretly hoping you'd be a real mini trucker, but I am sadly mistaken that you are doing it this way. I even grabbed fresh blades the last time at Home Depot because I just knew we were gonna clearance those fenders one day. I just knew it.

nakman
06-18-2009, 05:17 PM
:lmao: Ah, on the contrary, instead I'm doing my best to breathe a little 80 elegance into the mini truck world, one mod at a time..

DaveInDenver
06-18-2009, 07:18 PM
:lmao: Ah, on the contrary, instead I'm doing my best to breathe a little 80 elegance into the mini truck world, one mod at a time..
Yeah, I fought that battle for a while, too. Using OEM parts, OME suspension, etc, etc. Eventually it wears you down and you start looking for ways to do it cheaper and cheaper until one day you realize you're posting hacks and mods on Yotatech and you run out of the room screaming, spilling your Natural Light all over your new Vans sneaks.

nakman
07-04-2009, 03:32 PM
Well that was fun. so fun, in fact, I did it twice.. :doh:

the blocks give you two options: 3/4" back, and 1" back, and based on my analysis with the 2x4's I opted for the 1" adjustment, thinking that if I over-shoot a little that's ok since the tire will move forward when it flexes.

Here are some before pics:

nakman
07-04-2009, 03:35 PM
The install was pretty straight forward, only thing I didn't like is some amount of stress placed on my stock length brake line, I'm tempted to swap that out with a longer braided one but that's for another day, it didn't break. So with the 1" adjustment, I had to ditch the bump stops on top of the leaf spring, since they locate on the spring pin. I have a feeling those aren't used anyway... but you can see how close the front U-bolt is to the spring pin, showing the 1" of movement backwards.

nakman
07-04-2009, 03:42 PM
So that was yesterday. I took it to the car wash last night, and there's a ramp behind the car wash here in Broomfield (near the tracks, behind Great Scott's Eatery ;)) where I tested it out. And dang it, it rubs in the back now :mad:. so I went too far...



so this morning I do it all over again, and flipped the lift blocks around so that I only moved the axle back 3/4", instead of the full inch. Much better now, in fact no rubbing at all today when I went back to the car wash ramp and fully stuffed a tire... the other tire was actually in the air :eek: so I'm going to guess this is about as stuffed as these tires will get :D

you can see the difference, again comparing the spring pin to the u-bolt.

nakman
07-04-2009, 03:49 PM
My only other issue is my e-brake cable runs across the leaf spring, so 3000 e-brakes from now I may start to see some fraying of the cable, or may wear some of the spring paint off. I guess I could make some little extenders for that if it's a big deal... :confused:

And as I suspected, that bump stop would have been a mile away anyway. Here's a picture of the inside of the stuffed wheel, I labeled the frame bump stop... the spring one stuck up about 2.5" from the leaf spring, and there's easily 6" of gap there. Do I even need a bump stop?

Air Randy
07-04-2009, 04:46 PM
Through normal suspension travel, probably not. But the bump stops can come in to play if you nail a big pothole at higher speeds and totally compress the suspension. But it would have to go a long way before it caused any damage as long as your shocks have enough travel to not crush if the suspension flattens w/o a bump stop.

corsair23
07-04-2009, 11:05 PM
Looks GREAT Tim :thumb:

Jacket
07-05-2009, 10:15 AM
Thanks for the extra set Tim. :cheers:

As far as the bump stop goes, if you decide you want/need it, you could always drill out a new hole based on the new pin location. If you want to take it apart for a 3rd time and all....