BajaRunner

Hi All,

Just bought a 1991 V6 4x4 4Runner this weekend from my buddy. Drives great and both interior and exterior are in great shape too. Auto trans, but that is fine since it will be a DD.

Has a OME lift/suspension. He has replaced the passenger side CV boot 3x and now its leaking again. The CV angle is definitely extreme. What are my options here? Can you lower the differential down a little bit?

Some pics.

habanero

Is it joint angle, the boot lobes touching each other and rubbing holes into themselves, or replacement cvs that have the boots that crack up and die in about a year or so?

BajaRunner

Yep it is the angle for sure. The lift was installed about 6 months ago and he's gone through 3 sets of CV boots.

MudHippy

http://www.4crawler.com/4x4/ForSale/DiffDrop.shtml


That's hardly what I'd call extreme. What is it? 2" lift?

dropzone

iTrader: (6)

ORS has a high angle CV boot (i don't know if this is gen specific)
http://www.offroadsolutions.com/prod...inner-cv-boot/

you don't mention it if it is the inner or outer CV

You may consider contacting Nate at http://blazeland.us/
he may have a suggestion

BajaRunner

Thank you for the replies.

It is the inner boot. I'm wondering if its just the clamps that are the issue. I'll post pics here shortly. The angle seems awfully steep though from the differential down, and I looked closer and there are already some pucks in there to drop the diff down about an inch. I believe that it was installed after the first 2 boots tore.

I guess I'll just get under there and see whats the issue. I haven't had time to look closely.

Excited to get back into another 4Runner. I have never owned a 3.slow but it doesn't seem that slow at all compared to my 80 series. It actually feels nimble and sporty compared to an 80 with 35's. HA!

BajaRunner

OK I'm going to try and swapping with a new CV axle assembly since they are so cheap and see if that helps.

I noticed when my wife was driving it home that there appeared to be a lot of "motion" in camber when going over bumps. Do ball joints need to be replaced on these guys? I tried grabbing the wheel at 12 and 6 and it feels solid. Not sure if I am just being hyper sensitive.

Thanks for the help, been trying to search and read as much as possible.

BlazeN8

"Old Man Emu lift/suspension" for the front consist of thicker Torsion Bars and tweaking the shocks; in terms of valving and the length. Thicker torsion bars make for a greater spring rate for heavier loads and a stiffer suspension. None of which would add lift, travel, or increase the CV operating angle in terms of its range. What lift you are seeing is actually just a result of setting the angle of the control arms to a greater degree. There is a range the control arms can attain within a given arc path. Another way to look at it is wheel travel. If you are able to attain 6" of travel for a working limit range and the range is set in balance you would get 3" up and 3" down. When you adjust the ride height to "lift" the vehicle your setting it to run with a balance of something like 5" up and 1" down. Running with it like this will give you more ride height but reduces the droop. This puts the CVs at an angle still in the working limit range but the added angle will put wear on the joints and the boots.

Altering the bump and droop stops will affect the travel. Take a look at your bump stops. Are they Factory, Low Profile, or often Absent? If they are absent you may be able to get 8" of wheel travel. In balance you would get 4" up and 4" down. If you have ride height set for lift you might see 6" up and 2" down. The problem will be the CVs can only handle a range for 6" not 8" of travel. With the droop stop missing the extra 1" of droop is unusable as it exceeds the CV working limits.

If some one installs BJ Spacers this can upset things as well as it allows more droop than CVs, Ball Joints, and Tie Rod Ends are designed for. As for adding some spacers to drop the differential, a 1" puck at the RH and LH rear mounting points but not the front diff cover will lower the diff along the axis, through the inner cv mounting location, little more than 1/2" at best. Dropping the diff seems like a solution but the geometry for the inner CV joint to work is related to the location of the pivot points of the lower control arms. If the position is lower it may relieve the joint angle but then the plunge of the joint changes and the tripod plunge might bottom out on itself or pull itself apart. If the pull apart happens the boot rips. The boot can be over stretched or over compressed. The steeper the angle of the boot does both.

Converting the auto hubs to manual is a great way of preserving the CVs. That way your not rolling around as a daily driver spinning the CVs at extreme angles with the suspension cranked up. When your using 4 wheel drive your likely to be doing it at slow speeds for short distances.

BajaRunner

Thanks for the reply.

I understand that the lift won't be adding anything aside from taking away droop and turning it into lift height. Also I understand that this is creating a greater angle on the CV axles/boots.

To be clear, this is just a front ball joint spacer with OME rear springs. The PO told me it was an OME lift kit, but it is not. Its what you buy from Toytec. Just a ~2.5" lift.

My main question is that after all the searching and reading, I feel that this is an average height and does not usually require the use of any high angle boots, diff drops, or anything special really. It seems weird that the CV boot is tearing after a few miles, and looking for any input on what to check.

The previous owner was just replacing the boots, and might have been doing something wrong, not sure. I am going to try and replace the entire half shaft and see if that helps. Also I'll finally to get everything apart and check myself.

I might try adjusting the torsion bars down a little as well.

BlazeN8

There are some differences in CV assemblies from OEM and aftermarket. I tried to find photos in my archive but gave up. The inner tripod joint or barrel end cap from OEM is stamped to maximize plunge where some of the aftermarket end caps are flat. There are also some barrel depth differences. These will effect the way the CV joint performs. Also the accordion operation of the boot itself (collapses or lengthens) vary from mfg. The CV limitations has been a subject for performance seekers since the beginning. Clearance modification to the barrel, using Porshe or VW assembly, Spicer Slip Yoke, high angle boots, etc. Differential relocation, offsetting the diff, center mounting the diff are other solutions. If you search threads I started you can read about much of this.

As for your particular problem the key point that just came to light is BJ Spacer. This spaces the ball joint 1-1/2" allowing more droop than the CV is designed for. Search that.

BlazeN8

I found the photo of the inner CV joint that caps off the barrel. This is the stamped cap, I don't have a photo of the non-stamped but its easy to imagine what it looks like its just flat.