First time poster, long time lurker. Ive sent the same issue to Eaton but hopefully can find a fix here. I've searched and read every Super 10 thread I can find on here but this problem is not with splitting, only coming out of the 7-8 hole. Thanks in advance for your response.

I recently acquired a 99 Volvo single axle with a Cummins/Super 10 combination. Trans number is RTL-14710B. The transmission will split each gear fine..maybe a little slow. The problem is coming out of the 7-8 hole to 5-6 it will grind horribly and eventually catch. No amount of reving the engine to match rpm's or clutching will stop the grind. It's going to grind for a few seconds until it's done. Speed does not matter. High-low range or pre selecting range does not matter. Truck has not been under a load yet and I don't know the history of it. 940k on the odometer and I suspect fleet maintained for the first 900k but has basically been a yard truck for the past several years.

I had a few loud air leaks that have been fixed now, don't know about the last fluid change, but the problem does not seem to be with the splitter, only moving the shifter out of 7-8 to lower gears. The main 3/8 airline running to the had a t coming off that had been plugged sloppily but the fix had no change in the problem. It was leaking at the 3/8 line going into the transmission, but not bad. I replaced that fitting and it is a good connection now.

The shift diagram says range change takes place automatically between 6th and 7th gear. This transmission has never shifted automatically and I suspect that is where the issue is. In this automatic shift, would the selector switch move automatically as well? Is there a valve that controls this shift that is replaceable? Any advice would be appreciated. This is my first Super 10...am I driving it wrong? It drives fine in every gear and splits fine splitting each gear...just calls you every name in the book coming out of the 7-8 hole.


Thanks,
Jay