Should I worry about rear end problems?

[dparm1984]

Just got done paging through the "Any MS6 problems" thread. There's problems with any car out there, but it's still pretty small. I'm not that worried about them. I had an MS3 and it was very reliable.

Only thing that caught my attention was the rising number of clunking rear ends/differentials. What is the failure rate on this? I'd get a warranty of course, but there is still the hassles associated with having the car in/out of the shop, diagnosing, etc.

No plans to race it or anything silly, but it sounds like a lot of people just have this come up at random during normal use. Can anyone comment?

 

[chiefmg]

Personally I don't think most of the problems arose from normal use, but that is a whole can of worms and I won't argue with anyone ('Net wars FTL). I don't think you have anything to worry about, if you want some extra peace of mind there are several choices available to beef up the rear diff mounting. Turbine Tech has a nice front mount, for the rear mount you can get replacement bushings from them or get a cp-e or SU completely new mount. If you do decide to go that route I would recommend installing an adjustable rear sway at the same time. You will have everything apart and it will save you lots of frustration. The rear sway balances the handling quite a bit.

 

[Qwik6]

I didnt have any problems until I did a few launches. Then rear end was clunking. The dealer ended up replacing all the axles under warranty and the drivers side rear was the bad one. Havent launched the car it almost a year since and no issues what so ever.

I just added straps to the rear differential this morning and what difference. Something temporary until I throw out 500 bucks for mounts.

 

[Alladin]

I didnt have any problems until I did a few launches. Then rear end was clunking. The dealer ended up replacing all the axles under warranty and the drivers side rear was the bad one. Havent launched the car it almost a year since and no issues what so ever.

I just added straps to the rear differential this morning and what difference. Something temporary until I throw out 500 bucks for mounts.

Do the straps/mounts make a difference in launching or driveability?

 

[chiefmg]

Don't know about the straps, but with the mounts control of the rear is much better. For instance, I can now get the back end to step out slightly (without the TCS kicking on) making a turn from a stoplight, where before it wouldn't do anything.

 

[jonscapri]

Rear end issues

The rear differential is pretty good in design, and great for holding power, but the weak links are the axles, and the diff mounts. I'm in the midst of replacing my LR axle again, and rear diff mount for the 2nd time. the firsttime the diffmount broke was 2 days after I bought it with a total of 74 miles on it. They did the updated version, and it's toast now too.

Another thing to make sure is that you're tires are inflated to spec cold. This will save you some headaches. If you're tires are low it can too cause the clunk noise, and cause lowered mileage.

 

[BoostedSpd6]

Qwik 6 can u post up how u did the straps and maybe take some pics im interested in doing this too but cant find a thread on it anywhere, btw ken has a deal going on CP-E stuff over in the PG section on this forum i already pm'ed him about a rear diff mount u may want to as well..

 

[jonscapri]

I'd be interested in how the straps are setup too. Even though it's too late for my mount.

 

[Qwik6]

Are we allowed to link to another forum on here? Since I got all my info from other guys on another forum.

I bought $15 straps from autozone. Rated for 600lbs. I strapped the differential from both sides. I hooked it to the bottom of the frame where the suspension is near. Wraped the straps around the differential twice from each side. There is a wire on top of the differential. Most people didnt move it. But I found it very neccessary to move just not to chance the straps piercing the wire. Which was easy. Just cut it from the clip and there was plenty of slack to pull it towards the back and out of the way.

I will say this did make a drastic difference. Especially when taking off. My dif. no longer makes a loud clunk shifting to second. After driving it for 2 days one side worked its way snug to just a couple of clips and its very tight. The torque is much more instant when you hit the gas.

I dont have any pics right now of my current set up. I do of the old way which only lasted 15 miles since I had it wrapped around the swing arm if you call it. And the suspension going down pinched the strap and it came off.

 

[BoostedSpd6]

what if instead of a strap, there was a way to make a bottom brace and weld it to the frame..it would pretty much fuction the same as the straps..my only worry would be that the brace would snap at the weld's..but who knows im just throwing the idea out there as a way to get around paying 500 for mounts..

 

[bova80]

what if instead of a strap, there was a way to make a bottom brace and weld it to the frame..it would pretty much fuction the same as the straps..my only worry would be that the brace would snap at the weld's..but who knows im just throwing the idea out there as a way to get around paying 500 for mounts..

i don't know why you would pay $500 for mounts cause really all you need is the turbine tech front rear diff mount and then the bushings for the rear rear diff mount and thats like $275. i've been running it for over a year now and its been awesome and worth every dime, even the $100 for install. when it was up on the lift the guy showed me how the rear diff was sloppy and could be moved around by hand with stock mounts, once upgraded ones were installed that thing was solid. not to mention welding is not all that reversible and i think would be more harmful because at least the mounts allow a little movement if need be.

 

[OJ Bartley]

I didnt have any problems until I did a few launches. Then rear end was clunking.

Lately I've started to notice a sort of ... maybe grinding noise coming from the rear under hard acceleration in 1st and 2nd. Not really a clunking, but could that be the diff?

all you need is the turbine tech front rear diff mount and then the bushings for the rear rear diff mount and thats like $275.

No matter how many times I read over the info on the diff mounts and braces, I still can't decide what formula would be the best. I was leaning towards the CP-E rear diff brace, because I thought it was the OEM Mazda brace that was cracking. Would this be silly to upgrade without doing the TT front rear mount?

 

[bova80]

it was cracking because the other one was such a flimsy piece of crap that it would cause movement. with the stiffer front rear diff mount from TT you don't have that movement anymore. I've been running mine for over a year now with time at the track and no problems.

 

[OJ Bartley]

Awesome bova, thank you. Did the TT mount improve the feel of the car for day to day driving? Any significant increase in vibration?

 

[bova80]

oh yeah definately, a lot more solid on launches and no clunking. i didn't notice extra vibration but i do get a howling sound from the rear diff from 55-65mph, no big deal though, most cars with a rear diff do that anyways.

 

[jonscapri]

The only issue I've had is breaking the bolts off the front mount, but went overboard with some Grade 8 bolts vs the stock grade 5. The grinding noise could be the driveline rubbing up against the heat shield for the gas tank. Not to mention if you're having a problem with that front mount you'll end up having CV axle issues. Plus the add stress on the stock rear mount.

I've done the bolts on a few of these, and even though the stock mount works. for the most part, but can't handle any abuse. If you've got the money upgrade both mounts.

If you end up having axle issues, and knowing the way people drive the speed cars it can go from minor to major almost overnight.

 

[OJ Bartley]

The grinding noise could be the driveline rubbing up against the heat shield for the gas tank.

Thanks, I'll look into this. That first picture you posted is just horrifying. (nervous)

And thanks for the details Bova. I think I will try to go with the TT mount and see how she feels.

 

[jonscapri]

New Parts!!!

I finally got the last part i need to get this all back together.

For all those that think it's a pain to do the mounts it's really not that bad at all. Especially once you get the exhaust out of the way. PB blaster is once of my best friends LOL.

I got a pic what it looks like. This can happen with the rear or the front mount broken. Kind in mind that the you have a broken mount it will only compound damage done.

I'd take a look at the rear mount too. Mine started cracking. you can see where the rust started, and then the finally broke all the way through.
I was getting some minor thud noise. All I can say is if you can catch it all before it all goes to hell. the better.