Diff Locking issue

drftmx5 · Postby **drftmx5** » Fri Apr 02, 2010 11:06 pm

Hi everyone

I have recently bought a 1.6 MX5 after having wanted one since high school, Anyways I have a weird issue that I have never come across in any of the cars Ive owned before.

My rear right wheel seems to lock up as though the brakes are on, Its only that wheel. First I assumed it was a brake issue so took to brakes plus to have it looked at.

They rebuilt the calipers and changed the pads/ machined discs. It looked as if though the problem went away. Then a few days later I went to drive the car and it happened again.

While I was driving down the road a mechanical bang occurred then it went away. Straight away i took it back to brakes plus and the advised it is not a brake issue. I saw it on the

brake analyser they have and it looked fine.

They believe it is a diff issue but i have no clue what it can be. If anyone has had any experience with this issue or know what occurs when your diff is on its way out would greatly

be appreciated.

Also probably should mention I use this car for drifting and went to a Winton track day a week before the issue came. The car is also stock.

93_Clubman · Postby **93_Clubman** » Sat Apr 03, 2010 11:25 am

Unless you've replaced the diff oil recently & know the diff contains the correct quantity, initially I'd be draining the diff oil to see what volume there is, how it looks, & whether any metal is evident. If quantity is ok, looks clean & no metal evident, & you're sure it's a diff problem, then take it to a diff specialist.

drftmx5 · Postby **drftmx5** » Thu Apr 08, 2010 12:21 am

I changed the oil on the weekend and it looked more like liquid metal than oil !!!!!. Locking issue has seemed to go away though.

93_Clubman · Postby **93_Clubman** » Thu Apr 08, 2010 2:07 am

that's a good start - btw, what approx quantity came out?

drftmx5 · Postby **drftmx5** » Fri Apr 16, 2010 1:52 am

Well it seems that it hasnt solved the issue. It is so random dont have any idea what the problem is. Thinking of going to a diff specialist to have it looked at just the way it locks doesnt seem to be the diff. I have been using the car daily and when the issue arises usually omw home from work I just keep driving and it eventually goes away. Today I did it for about 5 mins and pulled over and my right rear disc was glowing red =s. Could it be the handbrake ?

In regards to the quantity if your speaking of the amount of oil looked like 1.5 - 2 litres

Postby **mx52nv** » Fri Apr 16, 2010 2:32 am

If we assume that the newly serviced caliper is not the problem, then it appears to be a sticky handbrake cable causing your rear right brake to remain engaged (thus the glowing red brake disc). The cable, spring needs checking and the adjustment nut needs to be looked at. Bring it to your nearest MX5 Specialist (look at the forum banners above and below) ASAP as that rear caliper, pad and rotor could also be damaged as a result.

It can not be a differential issue as there would be no reason for the brake disc to be glowing red (i.e. the brake caliper operates independently of the differential).

As for differential fluid, 1.5 to 2 litres sounds way too overfilled. The NA6 diff takes 650ml (from totally dry) which should be when it starts to flow out of the filler plug.

I hope this helps.

Les @ MX5 Shop