Camshaft question again

[jerry598]

Currently reassembling my 6.5. The machine shop 150 miles away installed the cam bearings and rear cam plug. I've installed the cam and it turns OK. I can detect no endplay by feel alone and can't find anything in any of my manuals about how to measure the endplay or what tool to use.

How is camshaft endplay measured?

And, is there any way now, with rear plug already installed, to check the clearance between the shaft and the rear plug?

[Robyn]

No Problemo

With the cam in the block and the retainer plate bolted on you should be able to push the cam back away from the plate some.

If you cant feel any for and aft movement in the cam it means that the plug is in too far.

You can use a rubber hammer and bump the cam to get the plug to move back.

Once the cam has the ability to move rearward from the retainer plate then install the gear and check that you have a little clearance for and aft between the gear and cam plate.

This clearance is small, maybe .005 to.010"

I always use a small amount of JB weld around tha part line of the block and cam plug to make sure it does not leak.


best

Robyn

[jerry598]

Thanks Robyn!

I definitely have no end play with the front retainer plate snugged up right now. If it was torqued to spec it would probably be tighter. When the engine was disassembled, I remember there was noticeable endplay in the cam at that time.

I'll try your method to get that plug moved rearward. I'll also be using the JB Weld and tapping holes for those rear cap retainer washers.

Thanks again.
Jerry

[Robyn]

Just be careful when you drill and tap that back flange.

6-32 is all you need. keep the hole far enough away from the plug that you dont hit the cups bore.

When looking at it it will be quite obvious where to place the holes.
You only need to use a screw that has 3/16 long threaded portion.

As long as the little washer will catch the edge of the plug your set.

OH BTW dont use any type of lock tite on these screws as the little allen heads wont hold to allow enough pressure to get the screws out.


Robyn

[jerry598]

The mallet technique worked like a charm, Robyn. Except that I should have reread your instructions a little more carefully.

Since I don't have a heavy rubber mallet, I held a 2x6 against it and smacked the 2X6 with a steel sledge. I had the retainer plate and front sprockets on it when I hit it, which were not part of your instructions. (at least I didn't have the oil pump drive gear installed).

Well, the retainer plate shattered into pieces, so I'm off to the salvage yard to find another one. Hopefully I didn't crack or weaken the front sprockets. They still look OK to the naked eye. Maybe I just used too much force.

If I ever have to do it again, I'd have an assistant reach into the block with a gloved hand or a hardwood handle and provide some support for the camshaft. Upon impact, the cam bounced back off the plug, dislodging itself from the bearings. Hopefully nothing was scored or scratched. All were covered with lubriplate.

Nevertheless, the rear plug clearly moved just enough to provide the necessary endplay, so the operation was a success. Will know for sure when I get a new retainer plate installed.

Next step is to check piston/ring/rod bearing clearance and install those babies.

[john8662]

There should be some play with the camshaft just freshly installed with the retainer present. As long as you have .005 - .010" you will be fine. This is measured with a dial gage on a magnetic base affixed on the front of the block.

This isn't how you set camshaft thrust though!

The camshaft thrust is controlled once the camshaft gear and IP drive gear are bolted to the front of the cam. To adjust this means adjusting (modifying) the gears. You're NOT likely to run into an issue here. The only thing you're after is making sure the back plug isn't in too far leaving the cam no room to move, even with the minimal thrust you'll have left with the gears bolted on. You just want some, usually around .003" - .005".

Attempting to do what you did with the gear bolted on, shatters camshaft retainer plates, ouch!

I usually tell the machine shop to leave out the plug in the back, because it's so close usually, so i set it myself. The plug needs to be installed with the edges flush on the back of the block, no further.

[jerry598]

Thanks for the clarification, John. It completely makes sense now. It was a stupid mistake for me to have the retainer plate and gears in place when I smacked it. The machine shop had recessed the rear plug about 1/32" into the block. It is now 'flush' with the rear of the block, not recessed.