possible differential failure

[240zchevyv8]

Hello again this frigin 240z with either make me or be the death of me, right just changed the suspension, fitted bumpsteer spacers, differential mount and gearbox mount all new, had an new propshaft made that is stronger than the old one( propshaft technology in rotherham £95 all in bargain in an attempt to get rid of a drive line vibration, the car is handling a lot better now, but i have noticed a slight grating sound when setting of hard, when i say grating its like metal jumping/banging/mashing but if i set of slow its ok no noise, i drained the differential oil from the R200 to check for metal shavings as i suspect the teeth are going, but found nothing amis im removing the rear cover tommorow to check the teeth for wear, i dont suspect the halfshafts themselves as they dont have splines to mash maybe it could be a bad input shaft on one side, the dif makes no noise while running nice and quiet, only setting of hard makes this noise if i spin the tyres, it may be the gearbox as sound does travel but the prop and input shaft were fine when i installed the prop, has any one suffered with a dif failure or gearbox failure with the same symptoms, ive got a spare R200 and halfshafts that im going to fit to rule these out but any advice may save me some time under the car,

 

[240zchevyv8]

i read on torque z that a common failure of the R200 are the spider gears could it be this that is failing, and are my symptoms the same, i thought R200 were supposed to be tough taking a lot of hammer??

 

[240zchevyv8]

Right removed the diff complete, stripped it all down found no wear on any thing, so rebuilt it thing is ive got a choice as to which dif i fit i have a R200 3.54 and R200 3.7 which would be best for my car with the engine gearbox i have in it, that being a 5.4 litre v8 with a 5 speed borg warner t5, next job strip down the gearbox.

 

[moggy240]

your not having much luck with this at the moment,i bet you was a bit disappointed that you could not find anything wrong with the diff.

 

[240zchevyv8]

in one respect yes, at least now i know the dif and half shafts are handling the torque, unfortunately it now points to the gearbox and sorting that could be expensive, it may be cheaper long term to source a stronger box??? unless i can some how strenthen the internals with upgraded parts, if i end up stripping the box i may as well wait till winter and run it all summer but not be as heavy footed.

 

[moggy240]

sounds like the best option to me ,at least you will get to use it over the summer

 

[Rob Gaskin]

I know you have fitted new mounts but are you sure it's not just the diff or prop touching something (like the anti-roll bar).

 

[240zchevyv8]

as of yet rob ive not ruled out anything, i havent been above 70 since to see if the vibration has gone, but it does feel better at lower speeds, if it still vibrates i think it will be a drive line angle problem, because it was fine before i stripped it down to move the engine further back and lower in the engine bay, so may be the dif is set to high??? will see this week end, by the way what do you think with regards to my dif selection problem 3.54 or 3.7 R200.

 

[240zchevyv8]

Right finally got to the bottom of my problems, took it to a garage to have driveline angles checked all ok , went for a spin 105mph now cured with new propshaft but could not live with with my car having a fault of sorts so last week removed the gearbox for a peek, and took it to my local gearbox rebuild firm, who could find no damage inside the gearbox, but discovered that the first propshaft on the car was not long enough, and because of this it was not seated into the gearbox far enough, and then to make matters worse with it being of inferrior quality and not up to the job it vibrated wearing the rear gearbox bush, so when i fitted a new stronger propshaft and gearbox and differential mount, the damage was already done, under normal driving it was fine, but put the foot down applying vast amounts of torque, and because the bush at the rear of the gearbox was worn it allowed the drive shaft in the gearbox to flex putting the gears out of alignment causing noise, new bush fitted and as good as new now no noises and only £60 to sort plus a few hours on my back, and to add a plus for me upon removing the gearbox, it turns out the car has the stronger world class t5 gearbox fitted, you can only tell once box is removed as they look identical from the outside. now the car is 100% its time to part ways, im listing it on ebay this weekend because at the moment its on axle stands as im just fitting new 300 zx vented discs with new calipers and aliminium spacers on the front total cost £400, those spacers were expensive, some one will get a cracking z with this one,all europe watch this space as its a left hand drive, hate to see it go but ive had enough.

 

[moggy240]

its a shame that you are selling now that you have got it to a 100% sorted but it is a sign of the times.good luck with the sale !!!!!!!!!