Oil for Volvo Drives

[Rob]

I've got a 1971 vintage Volvo 250B drive. Far as I know the drive has never been gone through. For the last three summers it's been harder and harder to get it to go into reverse after it has warmed up. It would take a few seconds for the clutches to engage and sometime you had to apply a little more throttle for them to engage at all. At that point I was running straight 30W motor oil as the manual recommends.

I decided before I would go to the expense of adjusting the clutches or going through the drive I would try different oil. Some time back I had an ongoing thread with Randy (BG) and Forrest on what oil to run in a Volvo drive. I believe Randy was running a hypoid oil. Forrest said when he got accredited on Volvo drive repair he quized the Volvo engineers about running motor oil in the drive because it's not really designed to handle shearing loads. (that's what hypoid is designed for) He said they maintained that motor oil was the recommendation. Ultimately he recommended a synthetic gear lube by Redline called MT90.

So I went on the Redline site, and sure enough, they had two products that looked to be a good fit. Both had special additives that change the coefficient of friction so the synchos in manual transmissions are much more efficient. One product (MTL) was slightly more viscous than the other (MT90) but both alleged to be similar to 10W30 motor oil in weight.

Because I was seeing the slipping after the oil warmed up, I went for the heavier product (MT90). I drained the outdrive and put in the new oil, voila, problem fixed! However, you could tell that the outdrive was pulling more horsepower spinning in the new oil and top speed went down a bit.

So here is the question: Do you think changing to the MTL product will still solve the slipping problem (assuming the friction additives were what did the trick) and not rob as much horsepower as the MT90 product? Or is there another better solution? Anybody have any experience with Redline they can relate?

[MOP]

I am for switching I run syn but wonder if the heavy weight is needed. My thinking is many including yours have run for 30 years or more on 30wt, way more still ticking then not. I would think but may be wrong that a lighter weight suffice and get some if not most of the efficiancy back.

Phil

[CHACHI]

I've got a 1971 vintage Volvo 250B drive. Far as I know the drive has never been gone through. For the last three summers it's been harder and harder to get it to go into reverse after it has warmed up. It would take a few seconds for the clutches to engage and sometime you had to apply a little more throttle for them to engage at all. At that point I was running straight 30W motor oil as the manual recommends.
I decided before I would go to the expense of adjusting the clutches or going through the drive I would try different oil. Some time back I had an ongoing thread with Randy (BG) and Forrest on what oil to run in a Volvo drive. I believe Randy was running a hypoid oil. Forrest said when he got accredited on Volvo drive repair he quized the Volvo engineers about running motor oil in the drive because it's not really designed to handle shearing loads. (that's what hypoid is designed for) He said they maintained that motor oil was the recommendation. Ultimately he recommended a synthetic gear lube by Redline called MT90.
So I went on the Redline site, and sure enough, they had two products that looked to be a good fit. Both had special additives that change the coefficient of friction so the synchos in manual transmissions are much more efficient. One product (MTL) was slightly more viscous than the other (MT90) but both alleged to be similar to 10W30 motor oil in weight.
Because I was seeing the slipping after the oil warmed up, I went for the heavier product (MT90). I drained the outdrive and put in the new oil, voila, problem fixed! However, you could tell that the outdrive was pulling more horsepower spinning in the new oil and top speed went down a bit.
So here is the question: Do you think changing to the MTL product will still solve the slipping problem (assuming the friction additives were what did the trick) and not rob as much horsepower as the MT90 product? Or is there another better solution? Anybody have any experience with Redline they can relate?Rob, if both the Redline products are a SAE 90 gear lube changing to the lighter one should make a difference,(on paper) real world, you probally would not get your RPM back unless the oil was hot. If you can find a full synthetic gear oil in a 75w90 viscosity you will be better off because a 75w90 has less parasidic drag when cold. The lower viscosity should help you get back some lost rpm. Ken

[RedDog]

Volvo makes a good syntheic (at least the label is branded as Volvo) - it is worth a try

[penbroke]

Not to change the subject but are you SURE you are getting enough movement in the linkages? If it doesn't throw the linkage in the drive far enough it will do just as you described. Slip a bit and then grab after a bit of time or sometimes a bit of throttle.

Mine is worn and will either work nicely going into forward or reverse depending on how it is adjusted. Not both.

My drive is a '66 200B and has been run with dino 75w-90 for at least 30 years.


Frank

[mrfixxall]

stick with the 30wt oil,,been running it in mine for 20 or so yrs not a lick of trouble....75w90 wil rob a little hp and volvo has a oil pump in the lower half to keep the clean oil flowing at all times....75w90 is like trying to suck peanut butter through a straw....

[MOP]

most all drive related shift issues are usualy the cone being worn and the float spring having lost its tension. The cones general condition can be checked by drianing about 1/2qt of oil out pulling the shift converter and looking into the upper cavity, also note the height of the cone it should be sitting in the mid way position between the cones upper and lower seat cones f it is sitting a bit low the float spring is bad. If you change the cone also change the spring, it is a very good idea to lap the cone into its seat cones.

Phil

[Rob]

The MT90 Redline product I am running is synthetic 75W80 gear lube, not 90W hypoid gear oil. The tip on adjusting the shift control is a good one. I've had the same problem in my Mastercraft for years. However I think this is different, first because it feels different than an adjustment problem in the shift control and second because it happened only when the oil in the outdrive warmed up. When you first started up and the oil was cold it worked just fine. I really think MOP is on the right track with the cone adjustment diagnosis. After all this drive is 35 years old and has never been touched (try to find a Mercruiser outdrive that can claim that kind of reliability!).

I'm still tempted to try the MTL product that is described as being lighter weight than the MT90 before diving in on the cone fix. I'm sure the "90" and the "L" in the names are not a coincidence. This stuff is pretty expensive at $8 a quart, but the drive only requires about 3 qts.

How does everyone fill their drive up after draining the old oil? Take the top cover off? I did not take the top cover off, but instead used a pump oil can to fill through the very small dipstick hole.

[BigGrizzly]

Your problem is a glased cone clutch assy. The easiest and best fix is lap the cones with valve grinding compiund. clean verry well and assemble. I do this on new parts also. This is a common problem. Dealers used to talk you into new parts so they were safe from problems and liability. I did my 66 16 in 1969 and it is still fin. I did my Corsican in 93 and it is still good today. And I still use gear oil in my drives.