Service interval: 348 updated chain tensioner pads & updated ball bearing?

My engine fell under the guide lines for the update, so I did them. My 348 is a '90, and has over 80k miles on the odometer. I did the ball bearing update, changed the timing tensioner pad, and the oil tensioner pad in my engine. The old roller bearing for the drive pulley was SHOT, and both tentioner pads were worn significantly. It was a good thing I torn it all the way down to change them out because it was greatly needed. One more thing. I also changed the bearing in the front cover for the timing chain, however, the bearing I used is questionable. Ricambi has a bearing from Hill Engineering that I would have used had it been available at the time.

Bottom line from my point of view, if it hasn't been done, and the engine falls under the update guide lines, it's a good idea to change them. At least that's what I did.

 

If you're going to replace the pad, then replace the bearing(s) since you have it all apart anyway. Just my opinion though.

 

Not replacing that rear bearing will make your 348 a ticking time bomb. No need to ask me how I know.

 

Chuck, which "rear bearing" are you referring to?

 

I'm very interested in this subject, Matthew. Thanks for sharing what you learned from your inquiries. It'd be great to know how your original components look/feel when you get them out.

Can anyone else offer any firsthand feedback on the longevity of the later factory components?

According to the TSB, my car falls well within the assembly number range that came with the updated bearing. With only 23k miles on the clock I'm thinking to defer the bearing change until the next major service (after the one I need to do this spring) but I'll be watching this thread carefully for indications that it should be swapped for the new Hill version sooner.

 

+1.

 

He is talking about this one. You'll find pics of it mid way down the page. It's located behind the timing chain sprocket.

http://www.ferrarichat.com/forum/technical-q-sponsored-algar-ferrari/438576-348-engine-out-major-15.html

 

The bearing (171177) is like $25. If the cover is pulled off, it's not worth it not to replace it. The cover bearing (170787) is now being made by Hill and it's $140. Again, not worth not replacing if the cover comes off.

 

It is the bearing on the rear of the shaft that drives the cam belt system. Ernie's thread shows the old style roller bearing and he dodged a bullet on that one. The later ball type is the upgraded bearing. You have to dig into the motor deeper to get to it but it is a must replacement if you have the original style roller bearing.

 

Im in middle of changing cambelts and stuff, and have a question about bearing under that timing gear. On my photo, is that the bearing that were basically garbage? Atleast its the same color that i have seen in some major threads. Gear was tight, but outer fence was partially loose.

Thanks
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That's the cover bearing (Part# 170787). The bearing in questions is at the end of that shaft (Part# 171177). Do a search on those numbers and you'll see the diagrams of it all.

 

The crap bearing **IS** 170787.

If the bearing has no markings on it other than the Ferrari part number, it is the new/suspect one.

 

oh, offcourse, my bad. My engine should have that upgraded bearing but i might still check it just in case. I just read some thread and there were same colour bearing that was called garbage, i don't particularly remember which bearing of that shaft it were

do those camgear fences have tendency to come apart? or was it just the lower

 

I thought you have the Hill version now for like $150? (A well known company had one made for me for like $500 because I did my work like 3 months before the Hill one came out)

 

There are 2 bearings that both may have issues. The original one where 171177 is located were needle bearings and fall apart. The cover bearing 170787 had issues if replaced using the Ferrari supplied non-SKF bearings and fell apart too.

 

hmm, that my front cover bearing looks pretty much same that ernie put in his engine in that on major thread, just by looking that seal and colour of it. Don't really like the idea of double sealing. i guess il have to take the cover off and see if theres seal still in place inside...bummer

 

Yes, the new Hill Engineering version is available in stock:

170787 BEARING - Ricambi America, Inc.

 

Wow, I'm totally confused. I thought the crap bearing was the "rear" one if it was a roller bearing instead of ball bearings. I see Ricambi just has a note "call" about that bearing. So if if you have the roller bearing back there, it obviously needs to be changed to the ball type so it doesn't end up like Ernie's, but... if your car has the ball bearing there, is that good for the duration, or does that bearing need to be changed at some regular interval?
As to the cover bearing I'm bummed out cause I didn't realise it was an issue so I didn't touch it last time around when I replaced the plastic tensioner pads and confirmed my rear bearing was the ball type, so I figured my next timing belt change I wouldn't have to pull off that pesky front cover. Guess that dream is gone.

 

The cover bearing that was an issue from what I understand is the one that Ferrari was selling as a replacement. It was junk. Hill is making that one now and Ricambi is selling it.