Rocker arm bushing replacment on 2.25L Petrol

[TJR]

Rocker arm bushing replacment on 2.25L Petrol

Has anyone sucessfully changed out their 2.25L petrol rocker arm bushing? I'm about to embark on this task and was looking for any pointers.

One thing I have noticed is that the replacment bushings in free state (i.e not installed ) already fit tight on the new rocker shaft. The shaft is .530" OD. After presing the bushings into the rocker armss, it's only going to make them tighter. Therefore I assume it just must be 100% required to hone or ream the ID of the bushings to size?
Any comments or techniques you've used w/ sucsess? Thanks Talbot

[gudjeon]

Take it to an engine machine shop. They press in the new bushings with the oil hole lined up with the one in the rocker. Then ream them out to get the fit as called for in the manual to match the shaft. I made some round stock on a lathe to remove and reinstall mine, but a good shop should be able to handle this.

[TJR]

Here's what I go done on the rocker arms tonight.
Stripped the rocker assy down after noting component positions.

There was far more wear on the rocker shaft than I expected. It needs to be replaced! The springs look a bit thin too (on the ends of a few).

I made a rocker bushing driver out of a Grade-8 5/8" dia bolt formerly used to hold the OE hitch onto the stock tow plate. the slighty under size dia is a near perfect fit.

I Cut off the bolt head, turned the OD down using a single point bit in the vise of a bridgeport and the 5/8 bolt shank in the spindle.

I used a 5/8 washer to back up the rocker arm and held it over a 15/16 deep socket. This arrangment worked like a charm. I was going to use a press, but the BFH worked just fine. All 8 bushings are out damage free.

Pressing the new bushing back in should be straight forward. I found a friend at work whose father has a sunnen hone to size the bushing ID to the replacement rocker shaft. (once I get the new rocker shaft in)

I Hope this helps out anyone else taking on the task..... Talbot

[SafeAirOne]

Ouch...Looks like there must have been a bit of oil in your sand!

My first instinct would have been to just bring it to a machine shop. Probably a $50 job and a lot less hassle, though I do like your inventiveness.

[gudjeon]

The under side of the rocker shaft is almost always worn on these older 2.25's. When the oil pressure gets low on a tired engine especially when PO's put in a regular weight oil. This is the first area of the engine to get starved for lube under pressure.

Perfect job for some good old fashioned DIY. A hone available is even better. The head and flywheel grind is the only work I had to get done by someone else.

[TJR]

I too thought there had to be grit or some other problem..i.e simply lack of oil. What is also amazing to me is that the copper/bronze lined bushings are worm, but not worn through. The shaft seems to have taken the beating.

And it further amazes me that the valve train is oiled throught the feed pipe from the block. That's not a large dia tube.

I suppose once the rocker shaft wears the oil will pass out over the top and less at the bottom (path of least resistance). Is it simple the oil flowing from the rocker shaft , out the holes and up the small hole in the top of the rocker arm that lubricates the valve tip and pushrod fulcrum?

I could have brought them to a shop, but any of the ones I trust are 30-40 miles away.
Plus this fills my craving to fabricate. The 50 bucks saves is minimal to the overall engine expense, but it helps buy the replacment valvetrain parts.

on my 2.25L , I had an engine shop do the engine work (.020 over) and assemble the short block. I'd love to have tried it all myself, but I'd still be figuring out taper on this, and taper on that. In the end one of the rebuilt 2.25l from RN is not that bad of a deal and a whole lot quicker. (for guys like me) . I had fun on the d'assy , clean and the short block build up. ...Talbot

[gudjeon]

Yes, the rocker is a weak point. The bushings made of bronze/brass is a material made to resist wear. It can do this better than harder steel with visible results as you have seen. Also, the bronze bushing can soak up and hold oil in the material better than steel. There is only that little feed pipe to get up there. If oil pressure/grade is not ideal... well you know.

Under pressure and out the underside of the bushing. Collectively, once worn, all leaky bushings can't be supplied by the volume pushed through that little pipe. Oil pushed out and down the fulcrum and splashed around. Yep, that's how its done.

[TJR]

I finally got it all back together.. New springs, shaft, alignment dowels,alignment bolt and rocker bushings. I opted to resurface the spacer washers with emery cloth on a flat steel plate.
Now to adjust the valves.

here's few r'assy pics. ... Talbot

Full Album Here..

http://s895.photobucket.com/albums/ac151/88seriesiii/EB_LR/ValveTrain/

[gudjeon]

Don't you love it when a plan comes together. I like the industrial green of the engine colour.

[Terrys]

Stripped the rocker assy down after noting component positions.

Oh damn, he said AFTER noting componant positions.