Am i being lied to?

[Da Big Blue]

Talking with a Mechanic (Kind of shady guy) and he told me if i am doing the lifters I also need to do the cam. this isn't true is it?
I think he is just trying to get me to bring my jeep into him.

[89grand]

That is absolutely not true! Bring your Jeep to someone else...it deserves better!

[ironhead]

I thought when you did one, usually you do the other? Am I confused about this?
IH

[Da Big Blue]

it sounded pretty far fetched to me aswell. This Mechanics response to everyquestion i ask is normally "Sounds like a bad tranny"
Seriously I took it in after i put in the new tranny because it was sputtering and lacking power, he looked at me and said "Take your tranny back get another" so i went to the mechanic down the road who actually took the time to look at it and drive and told me that i am only running on about 4 cylinders and that my bands probly need ajusting. sure enough he was right (Didn't charge me either)

[Serious Johnson]

'K:

Generally, cams & lifters should be swapped together. This is because the mating ritual between the two is rather violent, and the thin surface-hardened layer on lobes and lifters wears substantially on first fire-up.

Camshafts typically don't have a thick enough hardened layer to endure this more than once. Moreover, they wear at about the same rate as lifters anyway, so ought to be at least about gone if the lifters are.

If the lifters are being changed for hydraulic reasons, then it MIGHT be possible to save the old cam, but you have to ask why the lifters failed in the first place. If it was inattention to oil changes, then you can bet yer arse that the cam lobes are about shot too.

I'd give the same advice as your shady mechanic.

:-

[Powerstroked]

From what I remember, you can run new lifters on an old cam, but never put old lifters on a new cam. Probably why they sell cam and lifters as a kit. Hope this helps. If i'm wrong somebody will chime in. John

[OBX-AUTOMOTIVE]

HELLs-BELLs!!!! AUTOBODY PEOPLES EVEN KNOW THAT!!! YOU ALWAYS REPLACE THE CAM AND THE "LIFTERS"...DO TO THE WEAR ON THE OLD CAM!!! :rolleyes: smile.gif smile.gif

[89grand]

Well I agree that if you're changing lifters with an engine with alot of miles that it's a pretty good idea to change the cam but if mileage is the reason then I wouldn't stop with just the cam, I'd change the timing chain, push rods, rocker arms etc. I was saying that if you had a failing lifter for some unknown reason, that you can replace them without having to change the cam, in other words it's not an all or nothing repair. I mean there are reasons for changing the two together but you could eventually rationalize rebuilding the entire engine because of a lifter i.e if you change the lifters change the cam, if you change the cam replace the timing chain, if you replace the timing chain you should replace...

[RWC]

I've always thought you changed them together.

RWC

[Serious Johnson]

'grand:

Well yeah, if one low-mile lifter needs replacing for some mysterious reason, then it would be foolish to swap them all along with the cam, unless gaskets and labor cost more than cams and lifters (by the way, they do).

The original poster said that he was doing the lifters, plural. I ASSume that this means the old lifters are worn out, and thus likely the cam as well.

:-

[ March 11, 2003, 03:40 PM: Message edited by: Serious Johnson ]

[OBX-AUTOMOTIVE]

LET THE 2003 LIFTER "WARS" BEGIN!!! :cool: :cool: tongue.gif :D :D

[Powerstroked]

I totally agree with Serious Johnson. If ALL the lifters are being replaced because of failure for whatever reason,more than likely the cam is not far behind. I installed new Rhoades lifters on a cam that had been installed for about two years. That was four years ago and car still runs 12.20E.T. John

[bigblack'74]

i work at service station and i would NEVER sell only lifters sorry boys that just isnt the way it is done..do it rite the first time or dont do it all... just my2cents

[Crazy_Jeepman]

Anything can be done, being a good idea or not is another thing. I would never change one without doing the other. However this brings up several other questions, do you replace the cam bearings as well? Rebuild the engine? If you are taking a rig in to have the lifters and cam swapped, that can't be cheap. Maybe as smart to put in a rebuilt engine. Where do you start or stop?

[Lindel]

Let me give you a for instance when it's ok to swap a lifter. When you discover a bad one, right after cam break-in. During the cam break in, you might not be able to hear the lifter not pumping up, for whatever reason (loud exhaust, at about 2500 rpm?) That's the situation I'm in, right now. I don't have any qualms about changing out the bad lifter, at all.

[Shane]

I agree with the fact that lifters and cam should be changed as a set. But, why are the lifters being changed? If they just bleed down and rattle on start up then just change the lifters, if they are worn on the cam end then your cam will be worn out too. How is the oil pressure? Maybe the lifters aren't getting oil pressure and you need a new oil pump.

Shane

[country boy]

I would not replace lifters with out replacing the cam also. Thats like replacing the pinion gear and not replacing the ring gear.

[Bob Barry]

Well, not only do they mate for life, but once the lifter base starts cupping, it's basically a knife-edge grinding down the cam lobes as well. So, if your lifters are noisy, your cam is likely shot as well.

I found out the hard way that, unfortunately, a worn cam often means worn cam bearings, so a simple "solve the ticking valvetrain" job turned into a full-bore rebuild when I pulled the cam and half of the front cam bearing came out with it (no, they're SUPPOSE to be one-piece bearings).

[will e]

If I was doing it myself then I might just switch out the lifters. If I was a paid mechanic I would not do just the lifters because the customer would not really understand the risk and would blame me for not doing the job right.

[kong]

I think the only time that it's ok not to change the cam with the lifters is if you gots a set of them fangled roller lifters, but reckon that's really not the discussion at hand.

Old lifters=Old cam

The only thing I can think is that your old cam has proven itself over time, I reckon you could resurface your cam and then do new lifters, but then you gotta worry about new cam bearing sizes, new pushrod sizes. My question is this, why not replace both is it really that big of a deal? I've never heard anybody on the list say something like, "hey old cams are great!"; I personally love my new cam and lifters... just don't tell my wife! ;) :D

Kong

[shredby4]

If the cam is worn it will wear out the new lifters prematurely. They should be swapped together. If you decide to swap just the lifters, then make sure you use plenty of cam lube!!!!

[Da Big Blue]

Wow! alot more responses than i was expecting.
still a little confused though ;)

[OBX-AUTOMOTIVE]

Originally posted by Special-K:
Wow! alot more responses than i was expecting.
still a little confused though ;) :confused: smile.gif

[Agent Orange]

Special-k, key question here is why you went back to the shady mechanic. Either stick with the guy that adjusted your tranny and gave you good advice or fix it yourself based on the responses here.

[Nobby]

Ah the Joys of Machinery Maintentance you start off by thinking that you'll just adjust that carb and wind up rebuilding the whole engine! :D

Seriously though this is an interesting question and raises the issue that I always have in regards to engine work recommendations. Its really hard to make well imformed responses as every case is different and has different criteria. Add on to this peoples various experiences as above and you can get really confused.
Firstly if someone asks me should I replace my so and so, my stock reply is I'd have to see it first. I'll try to explain this somehow.
The problem with engine maintenance is that it usually winds up being a fine balance of various inputs. First input for me is what the books/my old lecturer say. Then from there you have existing parts condition, money, time, replacement parts availability and what your expectations of its reliability should be to name some. I'm sure there's more that are not springing to mind now. For me professionally its usually a case of we need it yesterday, you can't have any money, the engine is so old you cannot find that part anyway. smile.gif
Normally engine renovations recommend replacing this when you do that because.-
You are generally undertaking this work because of a high hours situation this would dictate that not just the failing part is worn. This means that other parts are just as worn and hence its no good placing good on worn. Tolerances will still be to big. The worn part will have a mating surface common to its old partner that over time becomes different to new. The old part can have a detrimental accelerated wear effect on the new part.

So have I broken the rules? Well yes and here is the thing. Usually I broke it not because I said of the bat 'oh that part isn't badly worn i'll leave it alone'. The process started by me saying I really should do that to, and then one of the following happened,
cannot afford it
no time
cannot get the part
or something similar.
my next response is then OK let me re-evaluate and see if we can get away with it.
I should just mention/totally contradict myself and say that if i just replaced some parts and they are not part of the failure then i could say of the bat they are OK leave them alone. Getting bored yet?

So to the question in hand replace the cam with the lifters?
I have already stated my stock answer in a previous thread of Special K's that yes you should. Breaking in of camshaft to lifters is tough on the cam lobes, done incorrectly with new cam/lifters can wipe a lobe in less than five minutes. You now take a 100,000 mile cam that's already broken in once and has wear on it potentially through the hardened surface/hardened surface now very thin and that old cam no longer looks favourable. Bob has already talked about the other wear that you can expect to find.
Next piece of the pie is that camshafts are not that expensive and readily availible, in the big scheme of things no big deal.
But ah the knock on effect, if you replace the cam what about the bearings. Yes you would need to appraise them there's no point putting a new cam in over tolerance worn bearings. Now to do the cam bearings is an engine out job. Where's it gonna end. :(
At this stage in the game things are getting out of hand and I just want to drive my truck. Well now I may well consider what the hell a new set of lifters only, the cam lobes don't look to bad. Carefull breakin by that I mean good quality cam breakin lube, make dam sure the engine will start straight away, pre-lube engine with an old dizzy shaft and a drill, fire up and get her above 2000rpm asap. See what happens! (You do need to know from experience what doesn't look to bad means tho.)

So what should you do?
Firstly I go back to my stock answer with out seeing it cannot really say. So therefore New Lifters = New Camshaft and vice versa
Camshaft has few hours on it, first response is hell if thats the case then why were'nt the lifters replaced also. OK, whatever, cam should be OK new lifters only .
Heck recent cam and lifters and say one bad lifter, then replace just that one.

I have 1-2 noisy lifters and there is a very good reason why right now I choose to ignore them. ;)

To sum up if this was a job I was undertaking on a Ship's Main Engine at the Dock that ran 24 hours a day 7 days a week 1500 miles out in the ocean and is hence the prime mover. Then its easy cam and whatever else she needs.
I'm now 1500 miles out to sea and something fails, i'll do whatever it takes to get her home. Now I know that would be a diesel etc, etc but you get my point.

This probably hasn't helped you at all and is as confusing as ever. Sorry about that. I enjoyed writing it though.

Oh yeah as already said while your at it fit a New Timing Chain and guess what New Chain = New Sprockets. :D :D ;)

[JeepBountyHunter]

Shoot I always heard, if you need to redo the cam and lifter's, it's time for the complete overhaul.........

[Shane]

For one thing a cam is not matched to the lifters like a ring and pinion set that are laped together, the other is that the lobe of a cam is ground at a very slight taper from one edge to the other, this spins the lifter so that it does not rub in the same spot over and over. This is why you need a special cam to run roller lifters, it has a perfectly square edge. I am not sugesting you don't have to change the cam when doing lifters, but new lifters will not wear out a perfectly good cam.

Shane

[letank]

when a lifter failed at 245 Km, i just replaced all of them..... now i have 296 Km on the original engine. remember that i went to Ouray and back

depends on how the cam is worn. look at the lifter and see if it is badly pitted !

everyone is right....

Michel
74 wag

[goofy289]

he told me if i am doing the lifters I also need to do the cam actually it is the other way around,new cam,new lifters. new lifters,whatever cam fits as long as it is in good condition.
http://www.cranecams.com/master/prevent.htm
good page on why to replace your lifters with new cam.
why the lifter replacement?noise?