Renault 25 Turbo whine

I have done a stupid thing here.
When I bought my GTD, I had it trailered to my home and have spent some time "fettling" it before I started driving it. I have checked and replaced various parts, as it was built in 1988.
The one glaring mistake I made was to check the gearbox oil level. I took the car for a run of about 10-15 miles but as I approached my home, I could hear a "whine" from the gearbox. It suddenly dawned on me that I had not checked the oil level at all since I bought the car. When I arrived home, I removed the filling plug and found I was able to put almost a litre of oil in before it came out of the hole. I started the car again (I have not driven it since) but upon engaging the gears it is still whining. It sounds a bit like a worn release bearing, but activating the clutch makes no difference, only having it in gear.
I am guessing that I'll have to pull the gearbox out to have all the bearings replaced as I'm sure I have done it no good at all. Is this something I could do myself? I'm a bit wary of any gearboxes as they seem to be a bit of a "black art" to work on.
Has anybody worked (successfully) on their own gearboxes, or is this best left to an expert?
Thank you.

Yes, I have searched the drivetrain forum.

 

[Paul W]

My 21 turbo box took 3 litres of oil ,so i'm not sure if you only had to top it up with nearly a litre of oil, what damage would be done. It will be worth a call to Chris Cole at Mach One Transmissions in a week or so when he returns to his workshop. 01952 222155

 

[Howard Jones]

John I may have some very good news for you. I had the same sort of noise and I just couldn't believe that it was the throwout bearing. It made a sort of high pitched wine that seamed to change pitch with engine speed. It also didn't matter if the gearbox was in gear or not, clutch in or out. Also the noise didn't change with gear selection.

Does this sound familiar?

Have a look at the throwout bearing. I think mine just dried up from setting in the box for years. When I inspected it it didn't have any sloppyness or anything really clear cut but it did seam dry. The races didn't have any resistance to movement. At first I though it was ok but it just didn't fell like any other T.O. bearing I've had in my hand.

So I got one from a delorian parts place and I was correct. The new one was more like the others I am familiar with. It has a slight tightness in the bearing, nothing that seams wrong but more like a new sealed bearing feels. It also has a sealed bearing.

So since you will be taking it apart anyway have a look at the T.O. bearing. Don't let a seamingly ok looking one fool you. I would replace a T.O. bearing with any other gearbox fix you might do anyway.

I hope you come out like I did.

Lastly I don't think a quart or so low on oil will hurt it in just a few miles. This would be about 1/3 low. Drain the old oil and put in some good quality sinthetic oil. Redline MTL or MT90 would be my choice but there are many good gearbox oils on the market. Also when you have the old oil out have a good look at it. Does it smell burned? Metal pieces? A lot of metalic looking contamiation? If not GOOD!

 

Thank you gents,
It seems I may have been a bit hasty about the gearbox. I took the car for a gentle drive today and there seems to be no untoward sounds from it.
Howard, I think you may be right about the throwout bearing. There IS a small amount of noise from that occasionally, but when the drive is engaged and the car is driving normally, all seems quiet. I guess that will be a job I'll have to have a look at before too long. As the car is fitted with an AP clutch, I presume that I'll NOT be able to use the Renault bearing. I suppose that's a question that'll have to wait until I have the gearbox off.
Thank you.

 

[Malcolm]

To fit an AP bearing to the renault bearing is a simple job if you have a lathe and the right 50p washer. The AP bearing is I believe about £50 and Roy & Anthony Lane at Techcraft should know which is the right one. When you get round to it, track me down and I would be happy to tell you how it needs to be done.

 

Thank you Malcom, I guess I should do this job sooner rather than later. It looks relativly straightforward to remove the rear end/driveshafts/gearbox. Is there anything I should be aware of?
Thank you.

 

[Howard Jones]

Be careful not to jam the dizzy against the rear bulkhead and dammage it. Then SLIGHTLY raise the rear of the motor with a floor jack, after the gearbox mounts have been removed, so that the gearbox is angeled upward at the rear. AGAIN SLIGHTLY!

This should give you enough clearance to pull the gearbox out from the rear. A engine hoist and some nice seatbelt material strapes work well if you must do this by youself.

It can be done by one person. I have had mine in and out at least a half a dozen times by myself. It is nice to have help never the less.

Of course you have removed the rear bodywork first off. This you will need a hand with. HEAVY!

* just detatch slave cylinder from top of gearbox and tierap it out of the way. You do not need to open the hyd line.

* Do not depress clutch while the slave cylinder is loose. Keep the kids out of the car.

*I took the time to center the input shaft to the end of the crankshaft centerline with a dial indicdator so I make a big effort not to disturb the location of the adapter plate. NOT EVEN A LITLE. I do not jack against it, ever.

* If you are interested in putting a neddle bearing in the end of the spiget shaft adapter nows the time.

* If you do it takes a standard Ford bearing.

* If you want to remove it ask and I'll give you a VERY easy way that does not dammage anything.

 

Howard,

Thank you for your advice. I shall be attempting this very soon. I think I will replace the standard bearing with a needle roller, I suppose it could be false economy not to. Yes, a way to get this out would be most handy.

 

[Howard Jones]

You should know that the one disadvantage to a needle bearing is if it should fail it will eat up the spiget shaft whereas the oillight bronze is softer and will not.

Ford uses the needle bearing on everything now so they shouldn't be a problem. Just take the time to aline the input shaft to the crank. Kinda a hassle to setup and check but a lot of gearboxes have died a early death because of sideloading the inputshaft due to missalinement.

My GTD was as close as dead on as possible when I checked mine the first time by the way. Does anybody else have any data on this?

Good luck take your time and have fun.