Final word for newbie

[SHOoff89]

OK, I have waited and waited for anyone to talk about the benifits of rod bearing replacement, but so far no one has quite touched on what I am looking for. So, here it goes....

I am troubled by all the talk about spun bearings here in the forum. Will replacing the bearings without a total rebuild extend the life of the bottom end of my MTX? I do not want to waste my money having this done if I should just do a rebuild. What other things should be replaced when having this done?

Anything anyone could provide as far as information for this would be appriciated, including estimated cost and how many days the car would be down.

 

[Mr Anonymous]

Did you try searching? The questions you ask have been covered many times.

Rod bearings are like most internal engine parts -- they wear. How quickly they wear is in large part a function of the driving and maintenance habits of the owner. Properly treated, these engines can easily last 200K-300K or more miles. There is no factory routine maintenance requirement to replace the rod bearings. If you race/track your car, lug it (high load/low rpm) or just generally abuse it the rod bearings will wear faster. If you don't know (or don't have confidence in) the car's maintenance history and it has 'high' mileage (everyone's definition is different, but I'd say over 150K), or if you're starting to hear the beginning stages of rod knock, then you might want to consider replacing them.

NAPA sells the Clevite CB1435P rod bearing sets for $7.49. That comes to a total of $44.94 for the required six sets. You will also need a new Fel-Pro OS30636R oil pan gasket and silicone set from AutoZone for $16.99. Figure about $12.00 for oil and a filter, $2.00 for an EGR gasket to use on the oil pickup tube, another couple bucks for a tube/tub of assembly ****, plus a few bucks for Plastigage (if you really want to do it like the Helms manual says). Depending on how gently you work and their condition, new exhaust manifold studs and a donut gasket may be required too. It's a relatively easy DIY project that can be done in a few hours (more than one, less than 8) for under $100 in parts.

Here a couple of other threads that I found using the Search function:

http://www.shoforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=17;t=004979

http://www.shoforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=17;t=007154

Here's another site with info: http://www.kurtmetros.com/bearings.html

 

[projectSHO89]

The rod bearings can be replaced in a day. The only additional parts needed is the oil pan gasket set and some more sealant. Total materials cost is about $75 unless there are additional problems.

The benefit of replacing the bearings is that if they spin, the crank will more likely be damaged resulting in additional expense to the point that the engine (and the car) may not be economically repairable. A catastrophic bearing failure can also result in a thrown rod which means a big hole in the engine block. Can't fix that.

A total rebuild is not always necessary as the piston rings seem to perform for very extend mileages. Unless there is an indication to do so, there is no need to replace them.

Rebuilding the whole engine, if required, will be a very expensive proposition. Not very many forum members have reported doing so. It would likely be a very large expense just for parts. Machine shop and other fees would definately add to the total.

Steve

 

[sdpatt]

Even after performing more than a dozen complete 60K services, I was reluctant to open up the bottom of the engine to touch the connecting rod bearings. I thought that was heavy engine work and for some reason was fearful of killing my engine if I did it incorrectly.

After pulling the starter, Y-pipe, oil pan, oil pickup tube and windage tray, I was looking directly up into the engine's major organs. The labor from that point on was slow and careful, but amazingly simple. I was thrilled to have performed such a valuable life extending service for my trusty friend.

Being careful and deliberate with replacement of each bearing and the torqueing of the rod end caps, I knew that I was ensuring the longer life and smoother operation that only the tighter clearances of new bearings could provide.

Sure I was a bit nervous when I plugged the DIS connectors back in and turned the key, but I was very pleased to hear the engine purr to life with a smoother, tighter audio soundtrack. I am very pleased that I spent the small anount of money and time to ensure my engine's long and healthy life.

The only reason not to perform this service after 150,000 or so miles of use is that you aren't confident in your mechanical abilities. In that case, pay a SHO friend to do it for you while you watch and learn. Just do it.

 

[svtman]

Scott,

With your mileage - did you check any of your mains to see what wear there was?

 

[SHOfun 93]

Scott,
I might employ you to do this service to my 93 when we get her all repainted and rebuilt. There is a slight clacking in the bottom of the motor at idle. Likely Rod Bearings I am sure.

 

[JoeHoe_SHO]

Yeah...if the time comes, as I'm sure it will. I will be paying someone to do this. I sure as **** would not attempt such a thing on my own. Texas is a little far away, but Trojan Man is local, and if he cannot...there is always Justin aka Foxwulfe. I would say Mark N. but I hear he is moving soon. I'm sure there are plenty of other SHO folk around my area that would gimme a hand for a fee...thats not on the planning board right now though. Gotta get my 89 back together, and then Adam aka Trojan Man and I will be going to town on my soon to be aquired 92s' tranny. SHO me the MONEY doh