Serpentine Belt Length Differences

My 89's alternator took a crap. I have a spare 4.0 out of an 99' sitting in my shop with alternator and bracket. Obviously the mounting bracket changed over the years. I also noticed the newer alternator sheave is a smaller diameter than the older alternator. Obviously Jeep changed the belt lengths over the years, so my question is, is the 99' belt that much shorter? If so than I probably need this belt.

I put this alternator on my Jeep...found out that my existing serp belt is too long. Worse case scenario I go and bug the idiots at Advance Auto and talk them into letting me find something that will work if the 99' belt length wont cut it.

Also, the renix alternator had what appeared to be an external voltage regulator. When I wired this newer alternator up it had ring connectors, and not the plug/voltage reg like the old alternator had so therefore I removed it. The new alternator (so I've read and been told) off the 99' DOES NOT have an internal voltage regulator because it was controlled by the ECU on the newer Jeeps. Where can I find an external voltage regulator for this alternator?

I've searched with no luck for these answers. I would greatly appreciate the help of anyone who can answer these questions.

FUBAR!

89 alternator is a Delco-Remy (GM) alternator with an internal regulator.

99 alternator is a Nippondenso that is controlled through the PCM.

Hit the salvage yard or parts store.

Take a look at the Rock Auto on-line catalog, you can keep the serpentine belt section from multiple years open and compare the lengths.

You might try taking a wire or some other non-stretchy cable / rope and following the path of the belt and then measuring to see how close you can get to one of the belts in the catalog.

Thanks guys. joe, I may have definitely had the wrong impression on the voltage regulator. My main question was the serpentine belt length as that was my main concern. Seeing that the 99' alternator will still require an external voltage reg, where can I find one? I will def. measure the length needed for my new serp belt so that I have a basis to order or match if need be. i just wish someone could verify there really is a diff in the renix belt and newer belt.

Dont know how youll get past the regulator issue but:
BTW these are Gates #'s

K060950 95-5/8" '96 - '01 Jeep Cherokee 4.0L w A/C
K060975 98-1/8" '91 - '95 Jeep Cherokee 4.0L w A/C
K060990 99-5/8"
K060994 100"
K060997 100-1/4" '92 - '92 Chevrolet (GMC?) G Series Van V8 7.4L
'96 - '96 Ford E Series Van V8 5.0L
K061000 100-5/8" '96 - '99 Chevrolet (GMC?) P Series Van V8 7.4 L w A/C, w A.P., w 140A alt, 145A alt
'96 - '99 Chevrolet (GMC?) C&K Series Pickup, Suburban V8 7.4L w A/C, w/o A.P., w 140A alt
'87 - '93 Chevrolet (GMC?) S Series Pickup V6 2.8L w A/C, w P.S.
'90 - '90 Chrysler Town&Country Van V6 3.3L, Dodge Caravan, Grand Caravan V6 3.3L, Plymouth Grand Voyager V6 3.3L Feb. 28, 1990 and older, w A/C
'93 - '96 Ford E Series Van 6 cyl. 4.9L w A/C
K061005 101-1/8"
K061010 101-5/8"
K061015 102-1/8"
K061020 102-5/8"
K061025 103" '87 - '90 Jeep Cherokee 4.0L w A/C
'87 - '90 Jeep Cherokee 4.0L w/o A/C
K061031 103-5/8"
K061033 103-7/8"
K061037 104-1/4"
K061045 105"
K061058 106-3/8"
K061066 107-7/8" '95 - '97 Ford Aerostar V6 3.0L w A/C
K061073 107-7/8"
K061075 108-1/8"
K061080 108-3/4"
K061098 109-3/8"
K061203 120-7/8"

RCP...that was a HUGE help. I thank you very much for that info.

-Evan

FastTRX said:

RCP...that was a HUGE help. I thank you very much for that info.

-Evan

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