getrag clutch, oil, and noise help

[c-moor29]

I just had my getrag rebuilt by a local guy that does good work, Installed it with a 13125 south bend 13 inch clutch/flywheel combo. every thing work well but the trans makes quite a bit of noise in neutral, 4th and 5th with the clutch out at any rpm under 2400. the noise will go away an neutral if you put pressure on the shifter in any gate, or fully depress the clutch pedal. In 4th or 5th gear it is only makes noise under a load accel or deccel, I think all of the noise can be contributed to the rubber clutch disk springs, and peter at south bend says this is most likely the case and said that it has no long term effects. he also said if I pull my clutch out and send it to them they would make me a quite clutch, which I would do but I only have 2 weeks before I am moving to oregon (1600mi), using my truck to pull the all of my stuff, and I am getting married in a week leaving no time to do any more truck work. I first filled my trans with full syn 5w30 (5qts) and put about 700 miles on it with no noise change. today I drained it (a few brass flakes but very clean, nothing magnetic) and filled it with 80/90 to see if it made a noise difference. no change in noise but shifts a little smoother. Here are my 3 questions

1. ) will engine harmonics traveling through the clutch into the trans eat up any bearings(isn't that the reason for dual mass flywheels?)

2. ) what effects will 80/90 wt oil have on the getrag

3. ) why in the H&!! did I not just swap in the perfectly good nv4500 I have taking up room in my trailer

 

[RedRamAndy]

Hello C-moor,

I can't answer all your questions, but I can help with a few points: I had the same bad noise in my transmission (all-original @ 175,000 miles). The rattle turned out to be broken torsion springs in the clutch disc, so I think you may be on the right track with the spring rattle. My transmission originally had ATF in it. I changed it to 90 wt when I did the clutch. The first time I tried to drive it in the winter, I changed fluid again. That 90 weight made each shift take about 5 seconds. It was thick! It was quiet though. I ended up going with Redline MTL and love it. I notice no winter / summer difference and the transmission is quieter than when it had the ATF fill.



Good luck.

 

[PToombs]

Regular 80/90wt is too thick, it won't lube the pocket bearing well enough. I run regular 15-40 motor oil in mine, works good. Lots of guys are running synthetic oils and have no problems. Just make sure you over fill by 1 quart, it's the one thing you need to do for longevity of the trans.