flatten the thrust surface on the front cover?

Roy L.

Jan 18, 2005
I'm replacing the stock timing gear set on a stock engine. The thrust surface on the front cover has a dimple. I'm thinking I need to flatten that area for new button. How would you go about doing this? How bad is bad before you should replace cover?

next question, Is it recommended to switch to a high-volume oil pump? Thanks
More important is did you completely disassemble to clean all the gear debris?
That will cause a spun bearing. Most people don't.
The stock pump is fine.
Comment above, he's saying all those chunks of nylon that came off the gear are in your oil pickup screen. Remove the oil pan and clean.
Me, I would get the roller cam button and not worry about the surface being completely flat. Dress it up by knocking off the highest ridges with sand paper and call it a day.
I will be removing the oil pan during this as well. Once I seen the missing teeth, I knew I was taking the pan down.
Would you have a part Number for a roller Cam button?
Should I put new crank and rod bearing in while the pan is down? who Knows how long the teeth have been missing? 70K mile motor.
cleanup the thrust wear surface with a milling machine. like was said, use the roller cam button.

I do everything I can to keep a GM cover going. that would include milling that thrust area flat and also epoxy a new piece fitted to the wear surface milled area if deeper - the same that was done on stage builds illustrated in the PowerSource book.

the imported timing covers available today are a mess. casting gasket surface by the crank sensor does not line up....need additional gasket maker there...the angle for the cam sensor hole is off causing excessive wear on the cam sensor gear...no back lash...

both Bison and Steve V have plenty of videos about timing covers. no need to retype stuff. see the videos on Bison's shop facebook page and Steve V's youtube channel.

TA Performance addresses those issues with their cover, when they are in stock.

how's the oil pump gear pocket? you can lap the cover or, if need be, buy a new wear surface plate for stock oil pump gears.

stay away from high volume oil pump. not needed for your setup and only causes excess loading / wear to cam sensor gear.

by oiling system design, main's 2 & 3 and rod's 5 & 6 will show best indication of bearing wear. pull caps 2 & 3 to inspect and go from there...
I used a Melling CB100 cam button, Rollmaster CS7020 timing set, removed the aluminum tab on the cover (very important with a double roller), and did the front cover oil mods.
The oil pump pocket looked very good, very light scratches that I couldn't catch with my fingernail. The pump cover needs lapped/ or replaced.

great replies, Thanks!
Rollmaster set is a really nice timing set. On a stock engine, there are some who'd rather choose a stock type timing set that retains the tensioner and might be a tad quieter than a double roller. just know that you have a couple of choices - rollmaster double roller or stock style. whatever you do, do not use the cheap timing sets using cast iron gears from the brick and mortar auto parts chain stores. those cast iron gears will wear quicker than you think causing the engine to jump timing, run like crap or maybe not at all once it jumps time.

as an option to the rollmaster, check out TA Performance's TA V1522B timing set - stock style, billet gears, 9-way keyway, for use with tensioner. the TA performance catalog has great tips and pics that the website does not. download the catalog and look up the timing sets.

cost wise, there really isn't much difference between the rollmaster and the TA 9-key silent set noted above. it's mainly for folks who'd rather retain a tensioner (and perhaps not do or pay for the machine work on the inside of the timing cover to clearance for a double roller). so, take a look and pick what would work best for you.

AND, as noted, while the timing cover is off, you might want to read up on doing the oil passage mods to the timing cover - as illustrated in the powersource book or written up by Earl known as the Earl Brown mods. just pay attention where to stop the drill bit - you don't go all the way up. plenty of written discussions and videos on the topic.

you have not done any machine work to the main bearing bore w/r/t billet caps so there is no need to worry about oversized gears for the timing set to account for align boring and honing.
Looking at the cover again. Maybe these scratches inside pump area are worst than I thought? What do you think ok or get a replacement cover?

As long as you’re in there, a different oil pump pickup tube is recommended.
Just in case the photos disappear again.
20IS2 is the Melling number.
224-128 is the Sealed Power number

It seems the stock pick up has trap door that lets debris in.

Post #3 in the following thread.

It seems the stock pick up has trap door that lets debris in.

Post #3 in the following thread.

The gear debris will get past the pickup screen and also the pump. I have pictures of the block and crank oil passages completely clogged of gear and caused a spun bearing. Don't take the easy way out. Exactly the same issue when blowing a stock head gasket.
Oh yeah, a milling machine for that wear surface, and get a magnetic drain plug if you don't run a factory style nylon coated timing gear.