Rotoflex to the rescue

[IsoDisco]

I signed on as SoMiss last week and asked about vibration at high speeds on a 99 DII with 111K miles...I checked the u-joints and found that there were grease fittings (apparently were replaced). I pumped the grease to all five fittings and replaced the rotoflex...vibration is gone!!!

I do have one question regarding the rotoflex replacement. How do you remove the bushing inside the rear drive shaft?

P.S. SoMiss is where I graduated from college, but looked a little feminine on thread...changed names...anyway, Thanks DiscoMike, Brooksa and Brian for the recommendations.

[brian4d]

Did you get your rotoflex from AB?

[IsoDisco]

LR Dealership

[brian4d]

do you mind me asking what you gave?

[IsoDisco]

$120.00

[jmrivera]

My dealer wanted $120 for it while roverconnection dot com wants $70... I found another source that wants about the same...

[brian4d]

Hard to replace, or just throw a wrench a few times?

[IsoDisco]

Six bolts...19mm ratchet and open end wrench...should have only taken 10minutes, but I tried to wrestle the bushing out with a pair of vice grips...wouldn't budge, so I did not replace it. Make that 20 minutes.

[Riflman]

Do you mind if I ask what the rotoflex does and if it can help me? I've got a 2002 Disco II, and RTE 3" lift and 265's. I get recurring blown seal at the connection of the driveshaft to rear diff, and sometimes the front driveshaft to t-case.

[rmuller]

Originally Posted by Riflman

Do you mind if I ask what the rotoflex does and if it can help me? I've got a 2002 Disco II, and RTE 3" lift and 265's. I get recurring blown seal at the connection of the driveshaft to rear diff, and sometimes the front driveshaft to t-case.

Rotoflex is the rubber coupling on the diff side of the rear driveshaft ... it is used to make the ride more comfortable and absorb vibrations.. problem is, when you lift the truck, the angle of it is now making the rotoflex wear out faster.. a lot of people replace it for a double cardan driveshaft with ujoints to eliminate the vibrations & rotoflex..

as for your seal blowing out.. is it the pinion seal on the rear differential? is the surface clean, and the breather line unclogged?

[Riflman]

I think it is in fact the pinion seal according to the shop. How do I tell? I don't think I have a rubber boot on the rear of the driveshaft. I think I have greasable u-joints but I will check.

[Riflman]

Originally Posted by rmuller

Rotoflex is the rubber coupling on the diff side of the rear driveshaft ... it is used to make the ride more comfortable and absorb vibrations.. problem is, when you lift the truck, the angle of it is now making the rotoflex wear out faster.. a lot of people replace it for a double cardan driveshaft with ujoints to eliminate the vibrations & rotoflex..

as for your seal blowing out.. is it the pinion seal on the rear differential? is the surface clean, and the breather line unclogged?

I have the rotoflex. The oil is coming from inside the diff and spraying out. It's collected on the flange. I guess that means the surface isn't clean, but how do I tell if the breather hose is unclogged? The rotoflex looks okay as far as I can tell and there does not seem to be a lot of play in the drive shaft. I called Bill but he was not available. Someone else mentioned a longer driveshaft? Will going to 285's change anything or is all of this because of the lift??

[Riflman]

Checked the truck and some pics and it's definitely the pinion seal. How often do these things blow out? My diffs were just rebuilt two years ago.

[Rovin4life]

the seals are crap to start with but with enough rust it can cause issues. you might want to put a new one one with a little aviation sealant and let the thing sit for a bit before driving it.

that might work a bit better.


I was on the road once and saw the leftover rear driveshaft after the lady was on a long trip from cali and the rotoflex failed and the shot the driveshaft like a rear missile.