serpentine belt conversion for CUCV

[Hoolio]

I'm kind of surprised that GM and/or the US Government didn't make the fan belt situation a little bit more beefy.. My M-1028 ILNG9N wears out belts too darned soon. I originally had a rust problem on the pulleys from years of sitting [ as it had 900 miles on it when purchased from Ft Mead]. After considerable sanding and cleaning , the belts now last 6 to 8 months, which is still to often for replacement.. I've used Dayco , Goodyear , NAPA. and others..In my estimation, this is one of the shortcomings of the CUCV in any serious operations. Hence the relatively poor performance record of this vehicle , second only to the M-880 series. My question is ; Has anybody attempted a serpentine belt conversion for this vehicle ?? If so what was the outcome ?? At the road department I work at we have 2 Ford F-550's with a serp belt that runs everything , including the hydraulic pump that seems to work well. Thanks Guys...Very informative forum.. Hoolio [Roy]

 

[aggopian]

Maybe mod from a 6.5 setup?

 

[ZiggyO]

Hello,

I have been through the short-lived belt issue on my cucvs. You may want to consider the belt quality and where you are sourcing them from before going through the trouble and expense of a serpentine retrofit. In my experience, dayco belts have the shortest life while gates belts seem almost impossible to kill (of course they are pricier too)............... I have also had problems with dayco serpentine belts prematurely stretching and failing on my suburban and caprice as well as the H1. I have been told but cannot confirm that dayco and other brands run several lines of belts all under their trade names but of differing quality and origins. Supposedly, places like pep poys and other big chains carry the lesser quality belts which do not hold up. (I had actually been buying my dayco belts from a local pep boys back when I was stilll in NJ-- after a slew of problems, I went to goodyear serpentines and gates v-belts sourced through a small mom and pop type store-- both were more costly but I haven't had problems since).


As additional food for thought, consider the redundancy of the v-belt system. On my last run back to NJ with one of my cucvs, I had the passenger side alternator toast an armature bearing-- I simply popped that belt and continued on the trip. Had it been a serpentine belt system, I would have been dead in the water.

Ziggy

 

[wdbtchr]

I think belt tension has a lot to do with belt life in addition to belt quality. I think if you've never used a belt tensioner you tend to over tighten v-belts. I think that may be the biggest advantage of serpentine belts the auto matic belt tension. Just my

 

[bryancarson]

I've tried Dayco belts and had them blow out 3-4 weeks after installation. after this happening twice I bit the bullet and spent the extra cash and went to all Gates belts and haven't had a problem since.

 

[Tinstar]

You usually get what you pay for.
Spend a little more up front or twice the price down the road.

I run Gates belts, hoses, thermostat and radiator cap.
Never an issue

 

[jnlperformance]

I completely agree and disagree. As far as belt quality, the better the belt the better the lifespan.

As for v belt vs serp I say serp is far superior. Less front end belt vibration. No matter how nice of a belt no matter how nice the pulley bearings no matter how perfect you tighten its always going vibrate harder than a serp setup. Especially the cucv I've noticed because of the length and span of the belts. The upper radiator hose clamp has a plate to protect from belt slapping hahaha it moves around so much.

But most importantly and one of the larger reasons I converted mine is because of the inherit 6.2 and 6.5 low end flaws. The cranks were and still are weak. Cast cranks are a no no weak dampers and in the case of the belt driven 6.2 the crank pulley is about as weak as they come. You can have them r e-trued but I forgot the name of the company that does that. Think they are in California somewhere. The 6.5 low end at least has a robust crank pulley. anything to increase the low end strength on the 6.2 and 6.5 is a good thing. An out of round and unbalanced crank pulley will assist and premature diesel death in these motors. I always recommend forged crank. Fluidampr harmonic balancer. Serpentine front end because of the usually unbalanced and out of round v belt pulley.

As far as my conversion I've got it all together. Getting to wiring up new alts. A bit tricky at first but I just about have it figured out. Gonna post a few questions about the orig si series alts that were on here. Another advantage is the newer alts have the rpm pickup already in. true in the case of my 94 65. Tachometer city.

The downsides are sofar... it was a bit of a pain in my arse to figure it all out sofar. Not any info out there on the serp conversion for dual alts. Most 6.2 articles covering this topic only had one alternator to deal with.

Does not matter which and or what you get. Better know how to weld and at the least have a machine shop nearby along with a starter and alternator rebuild shop.

I've got it all mounted up. Now my next major issue is the alternator wiring and isolated ground on pass 24v.

Your going to need at least 5-750 as a budget for the conversion. Your going to basically be rebuilding the engine front end your gonna need a new reverse rotation. Water pump and correct backing plate. The pulley and studs accociated. Front end seal kit. Water pump backing plate front cover crank seal . Might as well replace the timing gear set while your down there. as far as coolant crossover is concerned you'll need a 91-95 6.5 coolant crossover. 91-95 driver side accessory mounts. 96-02 passenger accessory mount. New t ensioners one gets used as idiler. New power steering pump. Be ready to purchase new because all the remanned I purchased are cheap crap. You'll also have to torch and bend one of the ps pumps tubes to clear frame. A pulley installer and remover for the power steering pump pulley horizontal alignment. At least one welded bracket conversion for passenger side alt bracket. Another mounting mod for driver side alt if you like identical alternator housings.

Ill let you know about the alternator modifications required and how it works out. Sofar I know im gonna need an isolated ground alt for 24v on pass side. I've read where I dont need that on the 12v driver side. Still reading schematics and info. Ill likely do a writeup with piks

 

[Chaski]

Don't forget a new fan too since it will also need to be reverse rotation.

 

[jnlperformance]

Oh and if you have a turbo on ur n.a. 6.2 you need a high flow water pump due to higher temps. Making the serp setup much more reasonable to do. Be sure you use the high flow water pump series from the 1986-02 6.5s I think they are 140gallon over the 6.2s 80 90s. Early model 6.5 pumps were on the low side too.

The reasons I did my conversion far outweighed not doing it. Will not be the same case with everyone.

Mine had serious balancer and crank pulley issues when I purchased it.

Someone added a gm4 turbo at one point but neglected to think about the higher temps accociated

Changed the crank to forged crank. Replaced the balancer with fluidampr. Had the pistons ceramic coated to prevent melting pistons ya. Its been a freak in ride yo

 

[jnlperformance]

And yes. A fan. Forgot to mention that. I have not gotten that far on mine yet. Im assembled but still need to figure alt wiring. Not gonna bother with a fan until I get it running. Fan will go on last. I get to keep my hands today lol

 

[Rutjes]

Sorry for brining up an old thread, but me and my buddy are thinking of doing the conversion on his 6.2. Does the harmonic balancer need to be swapped over?