engine and drivetrain Best Drift For Rocker Arm

[MattBeNimble]

Im about to do a tear-down of a e21 head. Any advice for the best drift to remove the rocker shaft? I have heard soft metal,plastic, drum stick and random others.  I am ok with investing into a new tool if I know exactly what I need to purchase. 

 

Please Help!!

 

Thanks, Matthew

[tim385]

A nice bit of brass rod.

[kbmb02]

The material of choice will likely be determined by how straight - or bent - the cylinder head is. On a nice, straight head, the rocker shafts will slide out by hand. If a head is warped and/or if rocker shafts are scored or were installed incorrectly, you'll want a aluminum drift and a really big hammer..... -KB

[tjones02]

Metric Mechanic used to sell a rocker shaft drift, probably still do, but I can't seem to find it on their website. I have one I got in '94, use it regularly. I could take a picture and measurements....

http://www.metricmechanic.com/

I've also seen a similar factory richer shaft drift as well.

If I had to make one... I'd take a bulkl steel rod about two feet long and grind a button on one end to help center the drift on the rocker shaft, and about 1.5" long section on the other that is cut down to about half the diameter of the rest so that the strikes from the hammer can flare it out without making it to big to slide through the head. The whole dia of the drift is just slightly smaller than a rocker shaft. This is a description of the Metric Mechanic tool...

HTH

[roadhog0]

Go to home depot and buy a 3 foot aluminum rod. It works perfectly and I have it stored and labeled for JUST that in my parents garage.

[TobyB]

Gaaaa- don't do it! 

 

If the head's bent enough to need a drift to get the rod out, you run a real risk of mushrooming the head of the rod,

which then kills the head, too.  Those rods are pretty soft.

Having spare blocks lying around, I've had some luck with bolting the head back

onto a block, then removing the rod.

 

When THAT doesn't work, see if you can grab onto the exposed end and twist.  One of the things that happens

is that the head gets distorted slightly around the bolt holes, and it clamps the rod.  A bit of a twist, and out it comes.

 

When THAT doesn't work, get that aluminum rod.  But make sure it's ALMOST as big as the rocker rod,

because if it's much smaller, it knocks out the center plug and then you start to get the aforementioned mushrooming.

 

But if you can avoid drifting (heh) it's always a good idea.  I've cut rods out of heads to avoid having to hit them

too hard on the ends...

 

Also, for reassembly, it's worth making a reamer out of an old rod (you cut a slot into it at an angle to form a cutting edge).

Then ream the holes so that the new rod slides more- or- less smoothly.  It usually takes out a tiny bit of metal around the

bolt holes, but it makes reassembly sooooo much easier it's not funny.  If you find yourself boring new rod holes

with this method, the cam probably won't turn, either.

 

Lotsa words, but I've messed this job up... more than once.

 

hth

 

t

[MattBeNimble]

Thank you all for your advice. 

 

I went to Lowes this morning. They had a (36") .50" diameter aluminum rod and a (36") .50" diameter Oak dowel that I picked up. 

 

My intake rocker shaft came out with minimal force using the wooden dowel and a deadblow hammer. The exhaust side however, was another story. The P.O. had pushed the blanking plug into the shaft and mushroomed the shaft ever so slightly. I had to use the metal rod and a lightweight sledge hammer to tap the exhaust rocker shaft out.  I think i will need to replace this shaft but  didnt add any scoring or damage to the head during removal. 

 

 

[Honolulu]

Lots of good suggestions here.  I suppose one could file down a mushroomed rocker shaft end if it were determined to be needed.  I've seen the "old pro" do much more surprising things - that worked.