ARB RD-90 Install questions

[p1michaud]

Ok folks, I managed to install an ARB RD-90 into the front diff of my 1999 Toyota Tacoma. I ran into a few issues but nothing major. One question I did have about the RD-90 is your CV dust flange location.

Frame of reference:
These pictures were taken while laying on the ground underneath the truck with my feet sticking out towards the front and looking up at the diff.

Question:
For those who have an RD-90 installed, what is your CV dust flange final location look like? If you look at Picture #1, I feel that mine is stuck out too far. For one, the oil seal is leaking (I’ve installed it too deep as well so that does not help, I’ll be replacing it this weekend). By having the CV dust flange out too far, the seal is too exposed for my liking and this could lead to early seal damage. If you can, I’d like to see pictures of your CV installed into the front diff. if you have an ARB installed as well.

Picture #1: Driver side CV in diff.

Picture #2: Driver side CV in diff measurement.

Picture #3: Passenger side CV as a comparison.

Cheers :beer:,
P

 

[p1michaud]

CV installation concerns.

Update:
I've been in contact with the good folks over at ARB and they have shed some light on the issue.

The dust shield is only 3 mm from the housing and they suspect that this is as a result of installing a steeper gear set (I've installed some Precision 4.56 gears). I'm not sure how installing new gears would cause this and have asked for a better explanation however they are the subject matter experts so I believe what they say for now even if I don't understand.

One member over on TTORA have PM'd me to indicate that this was an issue for their ARB RD-90 install as well. The sender has asked to remain anonymous and I'll respect that. Others have indicated that this was an issue with a True Track they had installed although it was a prototype unit.

The only solution at this time is to do the following:

1) Make sure that your CV is fully seated. A few things that can help ensure the CV is properly seated are to use a new "C" clip at the end of the CV axle and when installing hit it to push the CV in (as per the Factory Service Manual), rotate the CV 1/3 turn, hit it again and repeat untill it is fully seated. The job goes smoother if someone holds the CV in position while another pearson hits it to install it.

In my situation, I have confirmed that the CV is fully seated (i.e. the "C" clip is sitting in the side gear groove).

2) When you install the oil seal, make sure to leave it out as far as possible (i.e. don't push it in all the way). Stick with factory Toyota seals, they seem to last longer and seal better according this TTORA member.

I'm still concerned that the oil seal is too exposed and this may lead to pre-mature seal failure. I'll be doing a bit of experimenting this weekend to see if I can space the dust shield away from the shoulder of the CV and closer to the diff to close the gap a bit to maximize seal protection. Not sure if this will work or not.

Cheers :beer:,
P

 

[SEREvince]

I have the RD-90 and 4.56 gear combination. After almost exactly 1 year my passengers side seal has recently started leaking. During that time I also broke and replaced 1 CV on that side.

I just ordered new seals for both sides of the diff.

I would not recomend replacing the C clips from the CV! I have done it and it was a bear to get it back on and when I did finally get it on it was slightly deformed from having to stretch over the shaft. (After I sent one flying into the yard).

I have the skid off right now, I'll try and snap some pics tommorow when I have it on the lift (adjusting new SAWs).

Cheers

Vince

 

[Bighead]

I have the RD90 and PG 4.88s up front. I can get some pics of my diff this afternoon if you still want some. I'll check here again before I start working on my 4Runner.

 

[p1michaud]

Pictures please!

If you could, I'd like to get pics from both of you. :sombrero:
Cheers,
P

 

[Bighead]

I have Precision Gear 4.88s and an RD90 up front. The diff was built by Inchworm Gear.

Pic #1: Driver's Side
- I couldn't get a good picture with the ruler to show the measurement. The gap is ~5mm wide.

Pic #2: Passenger Side
- The gap is ~1mm wide.

 

[p1michaud]

Pictures.

I have Precision Gear 4.88s and an RD90 up front. The diff was built by Inchworm Gear.

Bighead,
Thanks for the pictures. From the pictures and your description I understand that your driver side CV sticks up a bit more than you passenger side as well.
I've got the new oil seal, so I'll be tearing into it over the weekend and update the post afterwards.
Cheers,
P

 

[p1michaud]

ARB RD-90 and CV location update.

I've managed to resolve the issue. Not eliminate it completely, but make it so that it works.

For your information, I have copied my correspondence with an ARB Tech about this issue. I’m more than satisfied with ARB’s customer service and technical supper. Top notch business and customer service.

There were two things working together causing my CV location issue and oil leak as follows:

1-The aftermarket gear set caused the carrier inside the diff housing to be shifted slightly in order to get a proper gear pattern. Read ARB’s comments below for a further explanation of this phenomena.

2-The “C” clip at the end of the CV that holds it in place in the side gear of the differential was broken preventing it from being properly seated.

Thanks to the information provided by members here and on TTORA I did the following to correct this problem:

1-I shimmed my dust seal on the CV by 0.020” [0.52 mm] to help close the gap and better protect the oil seal. The dust seal was still snug onto the CV and I’m not concerned that it’s going to move. You have to pry it off with a screwdriver to move it.

2-I replaced the leaking seal with a new one. The old one was actually installed when I installed the ARB locker two weeks ago, but I had installed it too deep into the housing.

Existing/old oil seal.

New oil seal (notice how it’s not set in as far into the housing, this ensures that is will contact the sealing surface on the CV).

3-I installed a new “C” clip at the end of the CV after making sure I had fished out all the pieces using a magnet. I was fortunate that it has only broken in two pieces. I placed it on a sheet of paper and made sure all of the pieces were accounted for.

Finally, here is a picture of the gap between the CV dust shield and the diff housing. It’s down to 1.5 mm and covers the oil seal much better that previously.

I’m happy to report after a 250 Km trip today where I had to use the locker 3 times to get me through some bad spots that the ARB RD-90 works great and the oil seal is no longer leaking. :wings: I’m going to continue monitoring it to make sure. Now that I’ve got the bugs worked out, I’m very happy with the locker.
Cheers,
P

Below is my correspondence with the ARB Tech. I’ve edited it slightly to remove any reference to his name and my name. If you need Tech support from ARB call (425) 264 1391 or e-mail them at tech@arbusa.com they will be more than willing to help you out.

From: ARB Tech
Sent: August 10, 2007 1:23 PM
To: P
Subject: RE: ARB RD-90 Install pictures
P,

I think a new seal will solve the problem and I don’t think the current location of the dust shield will affect the life of the seal, just make sure the seal is riding on a sealing surface of the shaft. With a steeper gear set your ring gear is thicker then before. Now when the differential is set up it will be further to one side then with the numerically lower gear, and with the dust shield sitting in a fixed location on the shaft and the circlip sitting in a fixed location on the shaft AND in the side gear the entire assembly will move together whichever direction the carrier is moved from it’s original position. This is not noticed on non-CV shaft vehicles because the shafts are allowed to slide in the splines and are not held in place by a circlip. Many differentials also have what’s called a carrier break where the ring gear deck height is altered to suit different gear ratios. Being that the RD90 is designed to suit all ratios the carrier will end up in a different location side to side depending on the ratio being used.

Best Regards,
ARB Tech


From: P
Sent: Tuesday, August 07, 2007 5:41 PM
To: ARB Tech
Subject: RE: ARB RD-90 Install pictures

ARB Tech,
You are correct, the dust shield does sit 3mm from the housing. You are correct again about the steeper gear set (sorry I should have mentionned that I'm running 4.56 gears now in the diff). I'm not sure how that would make the dust shield sit further from the housing, could you elaborate a bit? Is this a common occurence with aftermarket gear sets? Is it something I should be concerned about with respect to seal protection and degradation over time? I do have a new oil seal that was installed during the set up but will be changing it again this weekend. Hopefully that fixes the leak.
Thanks for following up.
Regards,
P


From: ARB Tech
Sent: Tue 07/08/2007 8:59 PM
To: P
Subject: RE: ARB RD-90 Install pictures
P,
It appears as though your dust shield is only 3mm from the housing. I suspect the dust shield sits further from the housing as a result of adding a steeper gear set, but correct me if I’m wrong with my assumption. As for the oil leak, I believe a new oil seal to be the solution as the dust shield does not retain the oil, the seal may have been damaged during R&R and not noticed. Please feel free to contact me if you have any further questions.
Best Regards,
ARB Tech


From: P
Sent: Tuesday, August 07, 2007 10:13 AM
To: Tech
Subject: ARB RD-90 Install pictures

ARB Tech,
Here are the pictures showing my CV dust shield and how it sticks out more than usual. The locker is installed and operating correctly however the oil seal is leaking. I confirmed that the CV is properly seated into the side gear. What would cause this?
The locker is an RD-90 installed into a 1999 Toyota Tacoma (7 1/2" IFS front differential).
Cheers,
P

 

[BajaTaco]

Hi P,

I'm glad you got it worked out. This is a great post, very informative. I have the RD-90 with stock gearing (4:10) and I too have the gap on the dust shield. I haven't had any issues with leaks though. I've had the RD90 installed for a few years now.

Finally, here is a picture of the gap between the CV dust shield and the diff housing. It’s down to 1.5 mm and covers the oil seal much better that previously.

I don't think you included this photo.

 

[p1michaud]

Opps!

Hi P,

I'm glad you got it worked out. This is a great post, very informative. I have the RD-90 with stock gearing (4:10) and I too have the gap on the dust shield. I haven't had any issues with leaks though. I've had the RD90 installed for a few years now.



I don't think you included this photo.

BajaTaco,
Thanks for the heads up. I've fixed that and added the missing picture.
Hopefully if this issue comes up for others, this information will help.

Cheers :beer:,
P

 

[flyingwil]

Swwwweeeet! Nice to see you got it all figured out!

 

[p1michaud]

ARB locker.

Swwwweeeet! Nice to see you got it all figured out!

Sweet indeed. It was a challenge, but worth the effort especially on Sunday when I hit the switch and got myself out of a few bad spots without breaking a sweat!

Cheers,
P