fuller 13spd transmission

I believe it's cause the manufacturing company recommends 50wt mineral oil compared to what was used before. I run 90wt synthetic, but in the old days I ran all purpose 85-140 gear oil. I think the thinner the oil , the noisier (whining) the trans will make.

 

Wasn't the viscosity requirement lowered to help with fuel economy?

 

I believe so, It's less drag in the drive train, but noisier. About 4 years ago (on my older truck which is park now cause a got a newer one), Ihad the transmission rebuilt or exchange, it was a RTO 12513, When I took out from the shop, it was louder then when i took it in, they told me it was due to the thinner oil in the trans, 50wt. and that is what the manufacturer wanted in it. I told him I didnt have a trans cooler so it might heat up quicker, he told me not to worry about it, I parked the the truck after about a year cause i got a newer one and I run 90wt full synthetic in that one.

 

Did you notice any difference in the way you shifted? Easier?

 

Nope.........

 

I guess I've never heard that whine in a 13 speed... my 15 was loude after I had it rebuilt. I complained to the rebuilder and they told me they would stand behind it if anything broke... it hasn't in about 500k mile and now it's actually pretty quiet again.

 

I always figured it was that extra set of gears in the back box that made it whine.

 

the 12513 in my 86 pete was so loud i'd have to shift down into direct to be able to talk on the cb.

straight cut gears, poor oiling to the rear bearings.