krmiller07 Posted March 19, 2011 Share Posted March 19, 2011 My 89 Pathy has developed an odd shifting issue. I have a 5 speed, and recently had the clutch, pressure plate and throw out bearing replaced. All was fine until about 3 months and maybe 5000 miles ago. I noticed that after I've driven it long enough to warm up the gear oil, it occasionally will grind slightly shifting from 3rd gear to fourth. It doesn't seem to grind like the syncro is going bad, because I don't really have to fight it into fourth gear by applying alot of lever pressure to get it to engage 4th gear. I shift it real slow, kind of coaxing it into gear. However while I'm engaging 4th it has, and make a clunking sound and feels like it kind of 'falls' into gear. When I rest mt hand on the shift lever while driving, it doesn't have any vibrations or feel like the bearings are rough or grinding. It also doesn't make any of the usual noises associated with a bearing(s) going bad. One transmission mechanic told me it sounds like the pilot bearing is either wore out or is going bad. Does anyone know if the pilot bearing is a 'bronze bushing' or one with needle bearings? I'm also wondering if this even a possible problem ? has anyone else experienced this problem with the 5 speed. I run Mobil 1 transmission oil, and have read the posts about Mobil One tranny oil corroding or causing pre mature bearing and syncro failure due to it's corrosive nature in Nissan gear boxes and gears Assembly's. I'd like to try and narrow this problem down before I pull the tranny and transfer case to fix this. I don't have alot of money to throw at this problem and would rather fix it than take a chance on another hi mileage replacement gear box. Any feed back or advise would be greatly appreciated. Thanks, km@frozenrotors.com krmiller07 Link to comment Share on other sites More sharing options...
nunya Posted March 19, 2011 Share Posted March 19, 2011 I had that issue in y 91 HB, it WAS a syncro issue but started after doeing a clutch and I didn't want to yank the trans until necessary. Hindsite shows I proably coulda did it when I had the engine out afterwards but I only milked the annoyance for a year or 3 until I junked the truck over a rotted frame Link to comment Share on other sites More sharing options...
Precise1 Posted March 24, 2011 Share Posted March 24, 2011 I run Mobil 1 transmission oil, and have read the posts about Mobil One tranny oil corroding or causing pre mature bearing and syncro failure due to it's corrosive nature in Nissan gear boxes and gears Assembly's. Ok then, step one is to get that stuff out of there. Get some GL-4 only oil in the right wieght (75-W90 IIRC) or some Redlime MTR-90, put 5.1 liters into the tranny through the shifter hole, maybe reserve 1 liter for Lucas oil stabilizer and that might 1/2 cure the problem and offset further degradation. B Link to comment Share on other sites More sharing options...
krmiller07 Posted March 24, 2011 Author Share Posted March 24, 2011 Ok then, step one is to get that stuff out of there. Get some GL-4 only oil in the right wieght (75-W90 IIRC) or some Redlime MTR-90, put 5.1 liters into the tranny through the shifter hole, maybe reserve 1 liter for Lucas oil stabilizer and that might 1/2 cure the problem and offset further degradation. B Precise1, I agree. I will drop the Mobil 1 tranny oil as soon as it's warm enough to crawl under there. I live in the 'Great White North' and mother nature hasn't released her grip on winter yet! The Lucas OIL Stabilizer you're referring to. Is that the stuff that pours like 'honey' and is about as sticky as well ? Thanks for the advise. krmiller07 frozenrotors Link to comment Share on other sites More sharing options...
Precise1 Posted March 24, 2011 Share Posted March 24, 2011 Sorry Bud, I didn't look to see that you are in ice fishing country. No garage?? Yes, that is the stuff. Some people like to run it in their motors and I'm not too sure about that, but I do think it belongs in gear boxes and differentials. I put some in my first pathy with the MT and it certainly didn't cause any problems. B Link to comment Share on other sites More sharing options...
krmiller07 Posted March 24, 2011 Author Share Posted March 24, 2011 Sorry Bud, I didn't look to see that you are in ice fishing country. No garage?? Yes, that is the stuff. Some people like to run it in their motors and I'm not too sure about that, but I do think it belongs in gear boxes and differentials. I put some in my first pathy with the MT and it certainly didn't cause any problems. B Ice fishing...thats funny ! I wish I were living back in Monterey! I tried some of that oil stabilizer in the FIRST motor in my truck. Ran great...for about a 1000 miles, and then it threw a rod out the oil pan! I'm going to use the Red Line tranny oil I bought, and then see if it makes a differerence. I'm still wondering about the pilot bushing causing some of this? Any thoughts ??? Thanks again, Keith Link to comment Share on other sites More sharing options...
Precise1 Posted March 24, 2011 Share Posted March 24, 2011 The Redline should work fine, many people here have used it and I do not recall a single complaint other than perhaps price. As for the pilot bushing/bearing, I'm not sure. I haven't done a lot of tranny work or examined these. Best bet would be to go to the Garage section in the pinned Factory Service Manual thread, download the earliest (1994) and look at the exploded view to see what that shows you. The tranny is the same over the years IIRC. B Link to comment Share on other sites More sharing options...
sewebster Posted March 25, 2011 Share Posted March 25, 2011 The pilot is a brass coloured bushing in my 91 5-speed. Seems unlikely to cause this sort of problem in my opinion. Link to comment Share on other sites More sharing options...
Kingman Posted March 25, 2011 Share Posted March 25, 2011 If it was the pilot bushing it would be doing it in all gears due to misalignment of the input shaft. Link to comment Share on other sites More sharing options...
JamesRich Posted March 25, 2011 Share Posted March 25, 2011 I put the lucas additive in my 5 speed with amsoil and everything is ok so far. I see where your going with the pilot bearing dragging and causing you shift problems but I think it would have to be galling very bad to cause that. My pilot bearing makes noise when the engine is cold and I let up the clutch but it doesn't cause any shifting issues. James Link to comment Share on other sites More sharing options...
krmiller07 Posted March 25, 2011 Author Share Posted March 25, 2011 I put the lucas additive in my 5 speed with amsoil and everything is ok so far. I see where your going with the pilot bearing dragging and causing you shift problems but I think it would have to be galling very bad to cause that. My pilot bearing makes noise when the engine is cold and I let up the clutch but it doesn't cause any shifting issues. James Hey James, Are you sure it's the pilot bearing making noise or the throwout bearinb? Does the Lucas additive cause for harder than normal shifting when it's cold. I know you live in LA, and the temps down there aren't nearly as cold as they are here. I guess my next or 'only' option is to dump the Mobil 1 tranny iol and refill with Red Line and see what happens. I just wouldn't think that Mobil 1 could do that much damage after just a few thousand miles. Man I've used it in non syncro-racing gearboxes for years with no problems. But then again that oil is frequently changed. Thanks Link to comment Share on other sites More sharing options...
JamesRich Posted March 26, 2011 Share Posted March 26, 2011 Hey James, Are you sure it's the pilot bearing making noise or the throwout bearinb? Does the Lucas additive cause for harder than normal shifting when it's cold. I know you live in LA, and the temps down there aren't nearly as cold as they are here. I guess my next or 'only' option is to dump the Mobil 1 tranny iol and refill with Red Line and see what happens. I just wouldn't think that Mobil 1 could do that much damage after just a few thousand miles. Man I've used it in non syncro-racing gearboxes for years with no problems. But then again that oil is frequently changed. Thanks Yes I'm sure its the pilot bearing. I have even diagnosed this problem over the phone once. I didn't notice any harder shifting when it was cold but it only got down to 20* this past winter. I have always used mobil one in everything I've had since 87 and never had a problem but what they claim happens here is something in the GL5 oil corrodes the metal that the synchronizers are made of. So I don't think the mileage matters as much as the time it has been in there. I would just change it out now and hope for the best. The lucas should help the synchros work better. Back when I was going to trade school my old instructor told be they would put STP engine oil treatment in manual gear boxes to help the synchros. The lucas should help in the same way. James Link to comment Share on other sites More sharing options...
unccpathfinder Posted March 26, 2011 Share Posted March 26, 2011 Ok then, step one is to get that stuff out of there. Get some GL-4 only oil in the right wieght (75-W90 IIRC) or some Redlime MTR-90, put 5.1 liters into the tranny through the shifter hole, maybe reserve 1 liter for Lucas oil stabilizer and that might 1/2 cure the problem and offset further degradation. B I use GL-5...not paying for redline...my syncro's ground in my 87 trans in 2nd and 4th when it was cold...i only had grinding in 4th on a quick shift and 2nd would grind when it was cold but if i went towards 4th and dropped into 2 it didnt grind...the 95 trans did the same in 4th...i changed the fluid and added the right amount and it rarely grinds... 87 trans had something like 220k on it and this trans has somehwere around 175k and they're both unopened... my syncro's are still somewhat good as i can still RPM shift through all the gears, 4th is difficult sometimes but most of the time not Link to comment Share on other sites More sharing options...
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