A couple of things I'm wondering-if anyone can help I am grateful

1) Where can trans pump pressure be checked? pressure specs. for idle speed/ high rpm?

2) is there a relief valve that can be adjusted/ replaced or spring change if pressure not right?


thanks,
-hystat

Not sure on #1 but #2 is a no. There is no way to adjust it. That is from the guy that rebuilt mine. If you need better preasure you have to change the pump. If you preasures are ok and you are still slipping then change over to Brass clutches and add a extra clutch in there by machining out the drumm, but you better know what you are doing for that one

There is a pressure relief valve built into the pump ,the valve is really just a check ball and a spring.If I can recall the spring is behind a pipe plug that can be seen inside of bellhousing. It can be shimmed with 2 or 3 # 10 flat washers if it does not already have them .If you go to mercruiserparts.com and look up 280 trs you can find an exploded view of the trans.If you want to rebuld the trans yourself it is not too coplicated.If you have any more questions feel free to pm and I can send My ph#.

Rob