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MG MGA - 5 Speed Tranny Lubricant

I used Mobil 1 Synthetic 75W-90 to fill my Sierra 5 speed tranny. I've had it out on the road about seven times for a 20 mile drive or so each time. When cold and shifting from first to second, if I don't slow shift into second I feel a definite "grumbling" going into second,.....like it has a bad synchro. A little of the same from second to third when cold. When the tranny is warmed up this goes away. The outside temperature has been around 50F. Last time I tooked it for a spin, I idled the motor in the parking lot more than I usually do. This made a big difference on the first couple of shifts, when before it didn't want to go into the higher gear. BTW..When I bled the clutch I had nearly 1/2 inch travel of the clutch arm, so this shouldn't be the problem.

To me 75W-90 is awfully thick oil but is recommended. Do you other folks with the 5 speed installed have the same problem when cold? When I was looking for the correct lubricant and asked the Ford dealer if they had Ford Synthetic part no. 5015547, he couldn't locate this product in their books.
What have you folks used to fill your 5 speed?

Ray
Ray Ammeter

Ray, I know Moss recommends Red Line but that doesn't seem to be readily available in this neck of the woods. I used Lucas Oil synthetic 75W90 in mine. It's a wee bit stiff on initial shift from first to second when cold, but quickly remedies itself as it warms up. Absolutely no grumbling noises though. Could it be that your box has a weak syncro?
Andy Bounsall

I used Redline synthetic 75W90. I have had no problems with noisy shifting etc. and no cold start problems. Occasionally I have a little trouble getting in second gear but I think that is my lack of feel for the gear positions.

Jim
Jim Ferguson

It could be the synchros, however when downshifting after my usual 15-20 mile drive I shift pretty hard (fast) into second and never have a problem. If it were synchros I would think it would grind going into second at that time.
There was a suggestion for Redline products from a Napa dealer when I was looking for Castrol Syntrax 75w-90, but I wanted to go by the guidelines given in the kit. I didn't know Moss recommended Redline.
Thanks for the info.
Ray Ammeter

Ray, I've only just installed mine s owon't be able to comment for another 3 months. I had a hard time finding any of the oils fecommended and finally found Castrol Syntac at Pepboys of all places. None of my high end parts places carried it.

Andy
Andy Preston

Thanks for your replies. I called the local supplier of the tranny and he said I put in the wrong tranny fluid. The manual supplied with the installation said to use one of five choices. I as stated earlier I put in Mobil 1 Synthetic 75w-90. However that is not the same as Mobil 1 SHC gear oil 75w-90.
SO I will be jacking up the car and will attempt to pump out the tranny lubricant. I have a E Z bleed and will give that a go. Then put in Redline MT90. I will let you folks know how easy ( I hope ) it is to pump out the tranny lubricant and refill with the correct stuff..

Ray
Ray Ammeter

Yes, 75/90 synthetic gear oil. Is that not what you had?
Andy Bounsall

Yes it was Mobil 1 "synthentic 75w-90", but that will not work. Per the local supplier of the tranny, it is too slippery for the synchros to work correctly.
Mobil SHC gear oil 75w-90 just is not the same as Mobil 1 synthentic 75w-90. Dang.

The latest:
I jacked up the car, put it on jackstands, removed the plug and got a "little" tranny oil out. I used a Mityvac (not E.Z. bleed as earlier stated) to pump what I could out. Attached to the Mityvac,I used a clear plastic tube with some wire coiled around it to maintain a bend in the tube trying to point it downward as it went into the hole. Problem (big one) is the gears are so close to the hole they will not allow the tube to get to the bottom of the tranny. I only got out about a cupful of fluid out. What a mess.

Ray
Ray Ammeter

Ray, if your removed the propshaft would the oil come past the rear seal. I don't know but it seems awful slow the way your doing it at the moment. Hope I got the right oil.

Andy
Andy Preston

This problem of no drain plug in the Sierra T9 gearbox has been discussed before. Below is a copy of two comments.


Fraser Cooper, Ontario, Canada, rfcoopermg@netscape.net

I fitted a drain plug to my Sierra 5 speed box while it was still dry and before fitting in the car.
It would be a bit of a pig of a job to do it after, but if you want to try:
There's a bulge or boss near the front of the box casing at what appears to be the lowest point. Inside the casing at that point is a circular doughnut-type magnet with about a 20 mm hole in the middle. I managed to drill and tap a 1/2-13 hole in the middle of the magnet hole (probably more good luck than management). I used a teflon gasket on the drain plug and safety-wired the plug to a small hole drilled in one of the webs of the casing.
I wasn't as optomistic as the Ford engineers, or perhaps they realised that the factory oil in the box would outlast the Sierra, anyway!



D Sjostrom, Massachusetts, USA

Fraser,
Did you know there was a magnet beforehand? Could one use iron filings outside the case to map the position of the annular magnet? A target for drilling maybe ;)

Thanks,
Doug


M F Anderson

Hello All,
I spoke with a local transmission shop while they pulled up the specifications for a Ford Mercury Merkur. Supposedly the same tranny as the Ford Sierra 5 speed. They said the tranny fluid for that transmission uses ATF. Automatic Transmission Fluid. Which by their estimate is about 30W. He thought 75W-90 would be ok in a warmer climate but too heavy around here. Washington State, USA.
The specs also say the trany fluid to be should be changed at 30K intervals.
ALSO ...and this is big for me, he thinks one of the lower bolts for the tail shaft when removed will allow the tranny fluid to drain out. It would be one of the bolts that goes into the tranny, but not into the tranny casing and protrude out. Make Sense? I would have to take a look at the tranny again and see which bolt would possibly drain the tranny fluid. If any of you folks have this tranny out and can check that out, I would be helpful.

Ray
Ray Ammeter

Ray,

The lower bolts mount to the new crossmember and pass through the transmission flange not into the gearbox. The next bolts up may open in to the gearbox but they are only slightly lower than the oil fill plug so I doubt it would drain much.

Jim
Jim Ferguson

Forgot the image. The lower center hole is closed off by the tail extension.

Jim Ferguson

Thanks Jim,

Looks like you have your 5 speed fully apart. Can you tell me, if I were to find a smaller diameter tubing would it be possible to insert it into the filler plug hole, either in the direction of the front of the tranny or the rear to avoid the gear directly inside the fill hole?
With the tranny in placed and the car on jackstands, it is a b---h to get the suction tube going in the right direction. DOWNWARD!
I remember from another discussion about the Sierra 5 speed, a person said they cut round hole in the MGA tranny tunnel near the 5 speed tranny fill hole, to fill the tranny with fluid when needed. I could do that, but would like to know first if it will allow me to extract the tranny fluid.

Ray
Ray Ammeter

Ray,

Sorry, I lifted the image from this site:

http://my.voyager.net/~quadrant19/Gearbox-upgrade.html

I installed my 5 speed as received from Hi Gear.

Jim
Jim Ferguson

This thread was discussed between 29/11/2008 and 16/12/2008

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