Im ready to order my parts for the timing gear change 88 2.5 duke motor. Stock part number for the SET (crank and cam gear) is 2542S a search on ebay comes back with a bunch of results. Most are Cloyes all Fibre Cam gear.One is a melling set but it doesnt show or tell what they are made of. In a search on Pennocks I see that Melling aluminum Cam gear set is part number 2538S. Ebay search on that number brings back only 2 timing gear sets one a Melling. When you punch in the numbers on the Melling sight it says that set wont work on an 88 fiero. Im sorry this is getting confusing my question is. WHAT IS THE ACCURATE PART NUMBER for a METAL gear set for a 1988 fiero 2.5 151 c.i.d. motor? Thanks in advance

Melling will tell you it won't work, but it does. The part in my instructions located at www.michiganfieroclub.com under techtips will work.

From my instructions:

http://www.michiganfieroclu...iles/4cyltimgear.pdf
You have two replacement choices.
Original fiber (aftermarket and OEM)
Aluminum (Melling (www.melling.com) number 2524 for cam gear or 2538S for cam and crank gear
- please double check with your auto parts store or with Melling, for the correct number)

If you choose the Aluminum gear (2524 or the set 2538S), Melling doesn’t show it as available for
the 87-88 Fiero 4 cyls

"Our parts catalog reflects the data from G.M. a to which part fits what year vehicle. We
have to follow O.E. recommendations for these listings to provide proper warranty
protection for the parts we sell. It may be true that the 2542S will work on a 1987
engine, but G.M. doesn't say so, and we can not warranty any parts used on different
years than what our catalog lists."

Regards,
Mark Richardson
Catalog Mgr.
Melling Engine Parts

Ok Jaskispyder thanks for your patience, your article and letter is one of my search results. I saw you have an 87 Duke ( which should be the same motor as mine.) I just want to be sure before ordering parts so part number 2538S stands. That IS the correct part number for a metal set of timing gears from Melling. 2538S Thanks

The metal timing gear set that the Fiero store shows on their website is described as a Cloyes set. But I bought one, and what they sent me was a Melling set.

[This message has been edited by TopNotch (edited 10-26-2011).]

I'm not sure if the PN is the same for the 88 as it is on the 84, I did use the Melling PN above for my 84. Do not use the fiber gear, I did and had to replace it a year later. I think they degrade over time and even sitting on a parts shelf for a number of years is no good for the fiber gear. I also think the metal gear makes for a slightly more responsive engine, there is less slop in the valve train and since the Duke is already a noisy engine, I didn't hear anything other than a slight gear whine with the metal gear. There is a note in the GM service bulletin about changing the gear without pulling the cam, you drill two holes in the metal hub of the cam gear and thread it for 1/4-20 and use a puller to remove the gear. GM recommends drilling a 1/16" hole into the oil galley plug that is directly behind the cam gear to aid in lubrication of the teeth.

quote Originally posted by Basic88: Ok Jaskispyder thanks for your patience, your article and letter is one of my search results. I saw you have an 87 Duke ( which should be the same motor as mine.) I just want to be sure before ordering parts so part number 2538S stands. That IS the correct part number for a metal set of timing gears from Melling. 2538S Thanks

Yup, we basically have the same engine, except for the oil filter and balancer. (well, I don't have that car any more, but... different story).

I wondered the same thing as you, but the number in my write up turned out to be correct. BTW, I did have a metal gear fall apart on my 292 inline 6 GM engine. so even a metal one can fail. I just wish GM would have bolted them on. Stupid.