Bought a new car 2WD Sapphire, doing some stalking of some of the previous owners threads on here one mentioned that he'd been through 4 rear diffs... And true to his word, after 20 minutes of ownership the rear diff pretty much exploded, broke through the case! I've now got the car in with a mechanic, and amongst a long list of problems, there is engine mounts being shot.

My question is, would vibration from the engine play a part in this car eating multiple diffs? The gearbox mount feels very loose too.

 

Sounds like that could do it and the mounts are common on those. Might be worth looking at the vibra technics ones and also consider having the prop shaft balanced...prop shaft services are good: https://propshaft-services.co.uk/

 

Thanks mate

 

I guess it will depend on what has actually failed on the diff. Normally on high power cars the planet gears are the first to break. But if something else is breaking, there might be something unusual going on.

 

Here's the note from Bara:CWP Pinion tooth Broken due to vc gear shaft breaking

Rear Cover Scrap

Vc Free

Gears badly Worn

Bearings worn

 

If the bearing on the pinion was worn I can imagine that the pinion and crown wheel will fail. The question is then what is the cause of the worn bearing. If the prop is out of balance it will wear the bearing of the pinion. But a badly balanced prop should be easily noticeable, as it would be shaking the car as well. I would also check the bearing halfway of the prop. I can't imagine that bad engine mounts would kill a diff. But the fact that the engine mounts are that bad might mean that the gearbox mount and prop bearing are also bad.

 

Yes prop bearing is bad too, and on the list. This list is getting longer... I was getting a big vibration in the steering wheel at pretty much precisely 65mph and then up. Would that be a symptom of the prop shaft?

 

Steering wheel vibration is most of the times caused by front wheels that are out of balance.

 

I've asked Bara what they think may have caused it too, see what comes back

 

It will be a process of elimination, make sure wheels are balanced. Change the worn mounts, check geometry, check any prop joints for wear. I had a vibration on a track car, it turned out to be a new but defective rear tyre…you would have sworn it was a front wheel bearing or warped front disc if you drove it.

 

I would not have been very happy Mr Simpson if the rear diff had exploded on a car I had just bought after only 20 minutes !!! It is not normal for a 2wd Saff to go through 4 rear diffs. My 2wd Saff has never had a problem with the rear diff in the 25years I have owned it. It was 380bhp when I first rebuilt the engine and has been 450bhp for the last 5 years or more. It does get "properly" used all the time not poodled around in.There has got to be something unusual going on for it to keep destroying diffs.

 

2wd diffs are made of glass if you have 2 things. Torque and grip lol

 

Not sure if Mr Simpsons Saff is standard or modifed? Surely if it was a really big power Saff it would have had an uprated diff fitted ? To go through 4 rear diffs especially if its standard power just does:nt seem right to me.

 

Some just fit them because there cheap. If he got it off someone that abused it maybe that’s why it went through a few. Who knows. I broke my first with 350bhp then second at 500bhp. I’ve a supra one now.

 

It's around 330bhp so not huge power, but Richard at Maine Automotive found the centre bearing was knackered, and the gearbox wasn't bolted in securely as the threads were stripped, as well as the engine mounts being shot. So hopefully with those sorted things will be a bit more stable under there... hopefully...