So my 03 G35 (AT) is at 100789 miles already,

Noticed some drips of oil months ago, and now it drips faster now. Dip stick shows way beyond low, Not sure why my oil pressure warning light doesn't come on

Assuming & from my last inspection, the shop told me it was the Rear Main Seal.

So when I do have it replaced/repaired, what other gaskets/seals should I replace at the same time? I know the Upper oil pan will need to be dropped.

&will also replace stock cats with Berk Non resonated test pipes to go with my HKS exhaust.

Will post pics later for attention

 

 

I would inspect the rotating assy while you're down there for play on the bearings as well as a preventative transmission mount replacement since it's got 100k on it.

 

Rotating assy? Im not sure what that is. & which bearings?

also any suggestions on the tranny mounts? Will I just need 1?

 

DEFINITELY do your homework on the transmission mount, read up what others have used and determine the level of harshness (and performance!) that's best for you. Stock rubber lasts for 100k and transmits the least NVH to the cabin, on the other extreme solid mounts last for millenia, require an occasional retorque and transmit ALL the NVH to the cabin. Urethane or other poly falls somewhere in the middle, some people like the "luxury" feel, some like the "racecar" feel... it depends entire on how you use the vehicle and what you like. Buy from a reputable vendor.

Another option is to simply wait to replace bushings until you have fully inspected the underside of the vehicle first, chances are you have a number of bushings that are worn if they're all stock. Some are difficult to diagnose however since they only show their age when torque is applied to the chassis, a great way to check is to pay a "diagnostic fee" to a local lube shop that has a pit, drive on the ramps over the pit, use large chocks around all wheels, have a tech shift from drive to reverse multiple times while you're under the vehicle with a good light and use a phone or something to video record the suspension movement and talk on the video to leave reminders for what needs to be replaced. It's pretty obvious when a mount is getting worn, there will be a significant amount of play under load.

Then you can order up all the bushings ahead of time and tackle everything in one shot.

As for testing the bushings on the rotating assy, typically I just grab the connecting rods one at a time with my hand and wiggle them around, should be 100% rock solid, same with end play on the crank, grab the counterweights for a handle and try to push it forward/backward, same thing, should be zero play. Wrist pins at the piston are a little trickier, rotate each cylinder to the downward part of it's stroke and you can reach up under to grab the edges from underneath. You can't really get any check on the crank bearings because one might be bad but the rest will keep it in check, visually observe the COLOR of them and make sure none are turning a light brownish color, they should all look identical from the side. Verify none of the bearings have spun, the dividing line will be the same as the bearing cap. Done.

A simple check that can help catch issues before they become serious and you're going to have full access to it while you're down there.