Rod bearings first time

[BTERRY1]

Well the inevitable is finally upon me. Going to do the rod bearings for the first time this weekend. Besides for Clark's and Texas Blake's any other good recommended reading or videos? Did a quick YouTube search with not much luck.

First time ever going in that deep. How bad is it really? Any first hand experience tips from your experiences not covered in tutorials that could be of some help? I have an 83 with a manual rack.

Thanks in advance

[John_AZ]

Here is another post & DIY for review:
Rod bearing replacement article? - Rennlist Discussion Forums

Get new rod nuts-Porsche updated.
Get the oil pickup tube checked or rebuilt. Do not forget the oil pickup tube "O" ring.

Search for many posts of oil pan gasket replacement. This is the biggest problem.

Search for "no oil pressure" on startup.

GL
John

[Techno Duck]

Not to bad on the n/a, especially with the manual rack!

Consider resealing the lower balance shaft housing while you have the crossmember out. Inspect the plug on the rear of the cover and see how bad the o-ring is.

I did a little write up on doing the rod bearings on my 951, a little different but the bulk of the work is basically the same.

Rod bearing and lower balance shaft reseal pictorial - Rennlist Discussion Forums

[HondaDustR]

The rod bearings themselves are easy. Get some green plastigage to do a quick check of clearances while you're in there. Have fun with the oil pan gasket. I enjoyed every second of the luxury of doing it with the engine upside down on a stand...don't even want to think about doing it upside down under the car, but the dental floss trick should be helpful. Make sure you get the front and rear part to seat fully into the curved channels, and use sealant on the corners of the block where the crank bearing girdle/oil pump join up with the block. My favorite is the silastic instant gasket made by permatex...Right stuff I think it was called. Use Acetone to clean the gasket and the sealing surfaces before assembly.

If you do the balance shaft housing, just get some real loctite 574. It's much better than the other anaerobic flange sealants usually sold in the auto parts stores (518, etc.) The first time I did it with the 518 and it didn't hold that well. Again acetone is the best gasket surface prep.

[VirginiaF1]

Originally Posted by BTERRY1

Well the inevitable is finally upon me. Going to do the rod bearings for the first time this weekend.

Good luck on your project mate..
May I ask, what prompts the need to replace them?
How many miles on your 944?
Thanks!

[BTERRY1]

Right at 200K. Developed a slight knock that would go away when warm. No longer want to push my luck.

[HondaDustR]

Originally Posted by BTERRY1

Right at 200K. Developed a slight knock that would go away when warm. No longer want to push my luck.

Does the oil pressure run low at idle, dip/sag as power is applied at low rpm in high gears (like 1500-2000 in 5th...has to be low enough to keep the OPRV closed or almost closed), or does the needle bounce with the knocking sound? Is there any metalic looking stuff in the oil or stuck to the drain plug magnet?

I'd look up at the cylinders once the pan is off just to make sure a cylinder or piston isn't on its way out...probably check the compression, too. The fact that you say it goes away when warm worries me a little on that. A rod knock would seem like it would get worse when warm as the oil thins out, but I don't know. Pistons usually expand to reduce the piston to cyl clearance when warmed up, meaning any piston slap would quiet down. That's the one downside to Alusil cylinders...they're pretty hard wearing, but once a cylinder starts going, it's pretty much gone, often due to the iron coating on the piston skirt wearing out or failing.

[BTERRY1]

wanted to thank everyone for there feedback getting me through this. fired right up and pressure is rockin. what a learning curve. hope the pan doesn't leak cause she is a mother Fr to put on from under the car.

Know is still slightly there but not as bad. at least i know if it is not my rod bearings

more investigation and feedback is welcome. i have to go on a trip so will post a vid when i return.

thanks everyone

[HondaDustR]

Nice. How did the clearances measure up with the new bearings?

[BTERRY1]

withing wear limits and consistent. old bearings looked pretty good too. Still have the knock but not as bad.

that is what i meant to say above

[HondaDustR]

Did you look at the cylinders from the bottom? No major problems?

It's most likely lifters. Not a bad job as long as you have a good quality long shank hex bit to get the inner bolts in the cam housing. SK or snap-on...the $40 is beyond worth avoiding the consequences of a cheap tool here! As mentioned, pick up a decent looking set of used OEM lifters from a parts car. The new ones sold are crap...they don't last and are expensive. As long as you had driven the car within the last day or two before the job, it will be obvious which lifters are the culprit once apart. They'll feel squishy. Just pick the best ones out of the second hand set and go from there. You can't necessarily go by how hard they feel if they've not been run in awhile, as they often leak down to some degree if they weren't stored in oil and it is not always possible to work the air out by hand. People say soak them overnight, hole side up, pump the piston, throw them away if they don't get hard, blah blah...take one apart and you'll see that it's not that simple. The air will always work out once started and run in the engine...whether they hold or not depends. I had a really bad feeling one out of my used collection pump up and work fine to this day. It depends. The job isn't hard once you get the hang of it and the gasket is pretty cheap. It does require removal and re installation of the cam belt obviously. Once you get the cam belt and the fuel rail off, the whole cam assembly will unbolt and come off in one complete unit. No need to remove the cam gear or the rear housing cover. Usually it's just freak bad luck if you have to go in a second time.

I dug up some threads from my past experience here.

Just how critical is a clacking lifter?

INA lifters worth messing with?


Here's the one with lifter disassembly pics and how to tell OEM from aftermarket INA, since INA made both.

cam followers/lifters/pucks ect.. questions