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Do you HAVE TO remove the TB to replace the rockers/lifters?
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=79249		 Page 1 of 1
Author:  JieselDeep [ Mon Jun 02, 2014 8:19 pm ]
Post subject:  Do you HAVE TO remove the TB to replace the rockers/lifters?
I did the TB and serpentine belt this weekend. Went incredibly well aside from not thinking about serpentine belt idler pulleys...time to pick up some 203 bearings and do a little rework on the existing idlers!.

I hadn't really looked into the work required to do rockers...mine are marginal based on the numbers I've picked up here on the forum. Does the timing belt have to come off to do the rockers? It's not just a matter of unbolting the valve cover?

Thanks,
Author:  geordi [ Mon Jun 02, 2014 8:54 pm ]
Post subject:  Re: Do you HAVE TO remove the TB to replace the rockers/lift
Yes.

Obviously you didn't pull the cam pulleys to replace the water pump as part of the timing job, or you would have gotten a great look at how the top is designed. This isn't a "valve cover" in the traditional sense, so much as it is the Camshaft Holder, Injector Guide, and Valve Cover, in one big lump of aluminum.

You will need to re-do the entire timing belt job and remove a whole lot more (the entire fuel system after the injection pump) in order to replace the rockers.

Think carefully about why you want to do this. My personal opinion about the rockers, is that you cannot detect whether they are actually in need of replacement UNLESS they have actually broken... Unless you tear down the top of the engine anyway. I don't think MAF numbers can accurately predict if any of the rockers are bad or not. If you DO pull the valve cover, however, take the time to replace the bolts with ARP studs. Whether you have a head gasket issue or not, the lack of consistency in bolt torque makes me think that the ARP installation is a good upgrade and might just prevent a minor problem before it happens. Cheap insurance.
Author:  The Scott McLean [ Mon Jun 02, 2014 8:54 pm ]
Post subject:  Re: Do you HAVE TO remove the TB to replace the rockers/lift
Yes unfortunately, our 2.8 doesn't really have a valve cover. More of a two piece cylinder head. The top houses the camshafts, the bottom houses the valves, and rockers. There is no way to keep the timing belt on the cam gears and remove the cylinder head. However listening to the knowledge of the guys here, and your experience with the timing belt. It's not that bad of a job. I'd say timing belt was 1/2 the job, injectors 1/4, cylinder head 1/4. Do research, buy parts a head of time. Decent job.
Author:  papaindigo [ Tue Jun 03, 2014 8:26 am ]
Post subject:  Re: Do you HAVE TO remove the TB to replace the rockers/lift
I agree with geordi on doing the ARP studs once you are in that far. Note that you need 2 sets of 10 each to replace the 18 existing head bolts. Save the 2 extra with their nuts and washers. As extras build up they can be passed on at a nominal charge to other members who might can accumulate enough to avoid having the buy the extra set of 10 studs when they only need 8. Might be worth a post to keep track of spares and their disposition.
Author:  amslube [ Tue Jun 03, 2014 4:02 pm ]
Post subject:  Re: Do you HAVE TO remove the TB to replace the rockers/lift
I would think a way to detect worn rockers/lifters is with oil analysis. From what I have seen here when these things go there is metal on metal wear which would spike the iron in an analysis report. I've been doing oil analysis yearly on my wife's CRD for the past several years and so far all looks good with 108K on the clock.
Author:  JieselDeep [ Tue Jun 03, 2014 7:14 pm ]
Post subject:  Re: Do you HAVE TO remove the TB to replace the rockers/lift
Thanks,

I just got the Blackstone Labs kit, so I'll send oil in for analysis soon!

I discovered during the timing belt replacement that I could not get either intake or exhaust locator pin to insert with any degree of feeling right...so I substituted 1/4" drill bits.

Once I got the cam pulley's off, it became clear that both intake and exhaust cams were about 3 degrees off (in opposite directions) when the flywheel locator pin was set.

That's now fixed and it's got a little bit more power as a result!

The belt actually looked great, no signs of cracking, no excess wear...it may have been changed once in its life, or life in Hawaii is nice to timing belts!

Thanks for all the help over the years!
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