Transmission Oil

veedublover12 · Post by **veedublover12** » Wed Jan 09, 2008 9:12 pm

Okay I know that any topic on oil can be a hot one, but I must know. Also I don't know how people on this forum feel about thesamba.com but I read on aforementioned site that Redline MTL would help shifting issues in a transmission. I am almost positive that my transmission is original, it has served me and my bus well but it is getting close to that time for a replacement, or a rebuild. At this time I cannot afford either, so I am trying to baby mine to squeeze as much life out of it as possible. I recently rebuilt my nose cone to fix very sloppy shifting (it worked) but before the nose cone rebuild, and after, I was and still am experiencing an awful grinding coming from my bus when I put it in reverse (only after the bus has been running for awhile, if I put it in reverse in the morning or after she has sat for a long while, no grinding) I also here a very less horrible sounding crunch when down shifting (this may be due to my rebuilt nose cone breaking in, as it has gotten less and less bad sounding as time goes on)
I have come to the conclusion that my syncros are worn pretty badly. Currently I have Valvoline 80-90T weight oil in my trans. Like I said I read that Redline MTL can help fix shifting problems, since it has the viscosity of a light oil, therefore allowing gears to mesh easier, while offering the protection of 80/90 weight. What are all your thoughts on this manner? And just in case you were interested here is the link to Redlines site http://www.redlineoil.com/products_gear ... tegoryID=7
One other thing, I have had the stop plate adjusted by my long time mechanic (which definitely helped, but did not make the sound go away) Just in case you were thinking of asking.

Cheers!

vwlover77 · Post by **vwlover77** » Thu Jan 10, 2008 5:10 am

I think the general consensus here is that the synthetic oil is good thing for your transmission.

BUT, based on your description, especially grinding when going into reverse, I'm wondering if your clutch is not fully disengaging when you push the clutch pedal down.

Reverse has no synchros, and shouldn't need them if both transmission shafts are not rotating, as should be the case with a bus that is not moving and a clutch that is fully disengaging.

I'm guessing that the reason it doesn't grind when it's been sitting is because the transmission oil is colder and thicker, so the input shaft does not spin as easily from the slightly-engaged clutch. As the oil gets warm and thin, the shaft can spin easier, and the grinding results.

I'd check out the clutch cable adjustment first. How much freeplay do you have in your clutch pedal?

vdubyah73 · Post by **vdubyah73** » Thu Jan 10, 2008 6:08 am

It does sound like a clutch adjust is a good idea. If that doesn't solve the crunchy downshifts also , it may be that your bus is a candidate for double clutching on down shifts. The purpose of double clutching is to match the engine input speed to the road output speed of the spinning gears. For upshifting you simply ''clutch, pull out of gear, let clutch back out briefly with foot of the gas then push clutch back in and engage next higher gear''. There is a certain timing to this in order to get the mesh you are looking for. Downshifting with the double clutch method is a little more difficult to match engine speed to road speed. ''Clutch, pull out of gear, let clutch back out briefly and stab the gas at the same time, while in neutral and heading for the next gear, push in the clutch and shift to the lower gear. Stabbing the gas in neutral, with foot off the clutch, revs up the gears from the input side to match the RPM of the lower gear you are trying to shift into. Pay attention to what the RPM or the engine sounds like while near the shift point for each gear when upshifting and try to match that sound for the gear you are trying to downshift to. Once you get the idea and feel for it learn to skip gears when downshifting to a stop because it isn't necessary to downshift through every gear every time. try to eliminate as much downshifting as possible. Timing is everything with double clutching. It's not so much do it as fast as you can, as it is feeling it out and anticipating where the gears are going very close to the same speed.

My opinion on synthetic is: it works well for lubricating and for maintaining viscosity through a large range of temps. However if your tranny has any leaks or weeps they will become worse with it's use. Synthetic does not create leaks contrary to popular myth. It's defenders are correct when they say, vehemently sometimes, "synthetic does not create leaks" it will just leak more easily from a weepy tranny. I would instead find a GL4 rated gear oil not a GL4/5, Napa has it, sometimes you have to ask the old guy at the counter for it sometimes they will have to order it from the warehouse. I have ordered early in the day and picked it up that afternoon. If the counter guy questions you just tell him it's for an old VW and the GL5 additives are harmful to your tranny's bronze synchro's. And the ACVWclub of America recommends not using anything but GL4. here is the Stay Lube part # and link from the Nap web site.

http://www.napaonline.com/MasterPages/N ... Automotive
NAPA® Online

Bill

RSorak 71Westy · Post by **RSorak 71Westy** » Thu Jan 10, 2008 8:20 am

I've been running syth in both my engine and tranny and they both do not leak, well the engine a couple small drops. My tranny seems to like the MTL.
I 2nd the clutch adjust idea....You need more travel.

vdubyah73 · Post by **vdubyah73** » Thu Jan 10, 2008 8:25 am

RSorak 71Westy wrote:I've been running syth in both my engine and tranny and they both do not leak, well the engine a couple small drops. My tranny seems to like the MTL.
I 2nd the clutch adjust idea....You need more travel.

As I said, if you don't have a leaky weepy tranny or engine synthetic is good stuff. If you have a 30 something year old tranny that has leaks/weeps it will get worse with the synthetic. I'm not bashing synthetic at all, it's good stuff just not for something that is either leaky or weepy to begin with.

Bill

veedublover12 · Post by **veedublover12** » Thu Jan 10, 2008 12:27 pm

I have no more than a half inch of play, should I tighten it down all the way? I replaced the clutch about 2 years ago, could it be time for a new one? What parts are the first to wear out? I think that if I put synthetic in, the trans will grind all the time, at this time whenever i need to go in reverse, i just turn the bus off shift then turn the bus back on. That way I don't have to grind the beegeesus out of my trans. Of course I cannot do this when downshifting. I have tried double clutching (it didn't help) but I think I was doing it wrong, I will play with it a bit more and see if I can get the hang of it. I recently replaced about a two foot section of clutch tubing. I got it from Ken @ The Bus Co.

He told me to cut about 1/2 an inch off of the end, because the tubing came from a 78, mine is a 69. I did this, but is it possible that I need to cut more off? I don't think it would make a difference, maybe just change the angle of the bowden tube, but maybe this is my problem...

veedublover12 · Post by **veedublover12** » Thu Jan 10, 2008 12:35 pm

If the counter guy questions you just tell him it's for an old VW and the GL5 additives are harmful to your tranny's bronze synchro's. And the ACVWclub of America recommends not using anything but GL4. here is the Stay Lube part # and link from the Nap web site.

http://www.napaonline.com/MasterPages/N ... Automotive
NAPA® Online

Thank you very much Bill this is very helpful. My transmission weeps a bit from the CV boot area, so using synthetic will probably make the leak worse. GL4 probably won't leak as bad since it isn't synthetic.

I am torn though, I don't want it to leak badly (Redline is expensive) but at the same time I would really like to fix the shifting issue. GL4 may be better for my trans, it is less expensive, but it probably won't fix the grinding at least as well as the Redline. I hate making decisions...

vwlover77 · Post by **vwlover77** » Thu Jan 10, 2008 2:53 pm

Please explain exactly what you mean by half an inch of play. Where are you measuring this half inch?

Don't spend any money on synthetic oil until you get the issue with reverse resolved. If your clutch is disengaging properly, there should be no grinding into reverse.

vdubyah73 · Post by **vdubyah73** » Thu Jan 10, 2008 5:08 pm

I wonder how you are determining your freeplay. If your your cable is loose from stretching. The pedal may move really easy till you hit some resistance. When you hit some resistance keep pushing and see if you hit a wall of resistance a little further down. What I'm getting at is, if your cable is loose and sloppy when you push the pedal the first resistance may only be the return spring at the bell housing lever for the throwout bearing shaft. and not the springs of the pressure plate. If that is the case then tighten the wing nut up until you have 1/2 to 1'' of freeplay. If the cable is fraying and breaking it may work for a bit and then get worse or break entirely.

Did that make sense?

Bill

RSorak 71Westy · Post by **RSorak 71Westy** » Thu Jan 10, 2008 7:33 pm

Just get under there and tighten the adjusting nut and make the cable shorter and you'll find reverse much better.

veedublover12 · Post by **veedublover12** » Thu Jan 10, 2008 8:59 pm

I am measuring the play at the pedal, I push the clutch pedal with my finger, when i hit resistance that is the end of the play. I can push the pedal with no resistance 1/2 an inch or so. I have a new Bowden tube and a nearly new clutch cable (it broke on me a few months back so i replaced it. When I installed the new one I put the L bracket upslidedown so the cable broke again awhile later, the 2nd cable I installed I made doubly sure that the L bracket was in right side up.) As for adjusting the cable, I twisted the wing nut till I couldn't get it any tighter, the grinding got a lot better (went from always grinding to only grinding in reverse and the occasional downshift). I cannot adjust the cable anymore, maybe I just have a bad clutch?
Also I definitely won't get synthetic until I get this grinding issue figured out.

vwlover77 · Post by **vwlover77** » Fri Jan 11, 2008 7:48 am

If the adjusting nut has bottomed out, you may need to put a nut over the end of the Bowden tube where it meets the bracket to get yourself some more adjustment range. I had to do this. See this photo (click on it for the larger image).

[albumimg]67[/albumimg]

Someone more expert than me may need to chime in here, but I'm wondering if something else might be going wrong, like the needle bearing in the flywheel not spinning freely causing the input shaft to the transmission to spin even when the clutch is disengaged????

vdubyah73 · Post by **vdubyah73** » Fri Jan 11, 2008 7:59 am

Do know what the Bowden tube is? It's the flexible tube that the cable comes out of before connecting to the clutch lever. If you lay some kind of straight edge between both ends of the bowden tube there should be about a 1'' to 1 3/4'' sag in it. if you make the sag a little more toward the 1 3/4'' end of the scale with some washers you might get enough more adjustment. You will have to disconnect the cable from the clutch lever at the bell housing in order to do this. Or, if you already have enough sag in the bowden tube, you could go completely hack and just remove the adjusting wingnut and throw a lose fitting hex nut or 2 on there as spacers to give you a bit more adjustment.

VWlover you beat me to it, I was going to suggest pilot bearing too, but the fact that he ran out of adjustment tells me otherwise.

Bill

veedublover12 · Post by **veedublover12** » Fri Jan 11, 2008 9:35 am

Ok I think I have a lot more than 1 3/4 inches of sag, my bowden tube looks a lot more extreme than VWlovers.

Also when I installed the bowden tube, the clutch cable was almost too short, I had to get my brother to help me pull the lever while screwing the wingnut onto the tip of the cable. I thought the more sag I had in the bowden tube the less clutch chatter I would experience, which was a big problem before I did all this work.

Post by **Amskeptic** » Fri Jan 11, 2008 1:01 pm

Chatter and poor disengagement can often come from the same issue. If you did not replace the pressure plate at the clutch job, it may have uneven diaphragm springs or a damaged contact surface with the disk.
Did you have any trauma when installing the engine that may have dmaged a finger on the pressure plate?

The clutch pedal freeplay must NOT drop below 3/4" or you WILL smoke the release bearing dead. It is a bandaid illegitimate attempt to cover up a symptom to crank down on the adjustment wingnut. My guess is going to be that you have a disengagement problem caused either by a dry or sticky pilot bearing in the end of the crankshaft, or a damaged spline on the input shaft of the transaxle that is hanging up the clutch disk. You are close to OK if it works well cold but starts acting up when warm.

The problem here is that your request for a better transaxle lubricant is still only addressing the symptoms. You are destroying the transaxle one grind at a time unless you fix the clutch.
Colin

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Itinerant Air-Cooled

Transmission Oil

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