91 V2500 Suburban - fan sits completely behind shroud opening, which part is wrong?

[guyindallas]

First post here, apologies if this belongs in a different section - mods feel free to move it.

91 V2500 Suburban 4WD, 5.7 TBI, factory front + rear AC (still on R12, recently confirmed pressures etc). Cools fine at highway speed, but at idle the AC gets warm and coolant temp creeps. Both recover once moving, so I went chasing idle airflow.

Done so far: new Hayden 2784 clutch (catalog correct - problem existed before the swap too), cleaned the condenser/radiator gap. Hosing the condenser at idle drops temps immediately, so it's airflow, not charge.

The issue that I believe is the culprit: the fan blade sits entirely BEHIND the shroud opening, not half in/half out (photo attached). Paper test confirms it's pulling air from around the shroud at idle instead of through the core. All the shroud mounting hardware looks stock (I think?). Radiator is aftermarket (previous owner), water pump history unknown. So something in the stack is a wrong part pretending to be stock.

Questions:

1. Water pump hub projection - anyone have the spec (gasket face to clutch mounting face) for the 87-91 R/V pump? Ever seen a replacement pump with a shorter hub pull the fan back out of the shroud?
2. Shroud variants - small block uppers came as 14021283 (no AC) and 14021285 (with AC). Is the AC upper meaningfully deeper? Would a non-AC upper on an AC truck leave the fan behind the opening like this?
3. What's the correct fan blade for an AC/HD 5.7 R/V truck, and do replacement blades vary in dish enough to move the blade plane an inch+?
4. Anything else that sets fan fore/aft position on these?

Planning to measure hub projection and pull the molded shroud number tomorrow if I can, but figured I'd ask before ordering parts. Thanks!

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One more just for fun:

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[HotWheelsBurban]

First post here, apologies if this belongs in a different section - mods feel free to move it.

91 V2500 Suburban 4WD, 5.7 TBI, factory front + rear AC (still on R12, recently confirmed pressures etc). Cools fine at highway speed, but at idle the AC gets warm and coolant temp creeps. Both recover once moving, so I went chasing idle airflow.

Done so far: new Hayden 2784 clutch (catalog correct - problem existed before the swap too), cleaned the condenser/radiator gap. Hosing the condenser at idle drops temps immediately, so it's airflow, not charge.

The issue that I believe is the culprit: the fan blade sits entirely BEHIND the shroud opening, not half in/half out (photo attached). Paper test confirms it's pulling air from around the shroud at idle instead of through the core. All the shroud mounting hardware looks stock (I think?). Radiator is aftermarket (previous owner), water pump history unknown. So something in the stack is a wrong part pretending to be stock.

Questions:

1. Water pump hub projection - anyone have the spec (gasket face to clutch mounting face) for the 87-91 R/V pump? Ever seen a replacement pump with a shorter hub pull the fan back out of the shroud?
2. Shroud variants - small block uppers came as 14021283 (no AC) and 14021285 (with AC). Is the AC upper meaningfully deeper? Would a non-AC upper on an AC truck leave the fan behind the opening like this?
3. What's the correct fan blade for an AC/HD 5.7 R/V truck, and do replacement blades vary in dish enough to move the blade plane an inch+?
4. Anything else that sets fan fore/aft position on these?

Planning to measure hub projection and pull the molded shroud number tomorrow if I can, but figured I'd ask before ordering parts. Thanks!

You must be registered for see images attach

One more just for fun:

You must be registered for see images attach

It's been a few years since I had my 90 R2500 5.7 Burb to look at....but I think that is the wrong fan shroud. The fan is supposed to be inside the shroud (hence the part name) not just for proper airflow, but for safety reasons too. With the fan blades exposed, it's VERY easy for stuff to get caught in it, and seriously torn up. That fan will take your fingers or hand off!

 

[guyindallas]

It's been a few years since I had my 90 R2500 5.7 Burb to look at....but I think that is the wrong fan shroud. The fan is supposed to be inside the shroud (hence the part name) not just for proper airflow, but for safety reasons too. With the fan blades exposed, it's VERY easy for stuff to get caught in it, and seriously torn up. That fan will take your fingers or hand off!

Thanks for the reply!

Yeah I am starting to wonder if someone put a wrong replacement on somewhere down the line.

If anyone has a photo of what one is supposed to look like, that would be appreciated! Perhaps the correct one has a longer shroud that goes over the fan?

Really wracking my brain trying to figure out which part is wrong here.

 

[guyindallas]

Seems the shroud on classic industries does indeed look very different: https://www.classicindustries.com/product/1989/chevrolet/v3500/parts/t79434.html


I wonder if the current shroud on my truck was installed when the after market radiator came on... and wonder if a stock shroud will even fit now...

 

[gmbellew]

shroud linked above looks an awful lot like the shroud on my 1990 v1500, and mine is original.

 

[ali_c20]

Welcome. The shroud is wrong.
Should look like this:

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[Smtty58]

For reference, this is my 90 CC, non AC.

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[xm20k]

My older (78) 5.7 had a deeper shroud like the ones others have pictured. OPs is probably aftermarket, could always add a fan spacer as long as it won't hit the rad. The fan closer could also help with it pulling air through the rad.

 

[Hunter79764]

Agreed, shroud doesn't look right. Any chance that's an aftermarket big block shroud or something?
How much clearance do you have from the front of the clutch/fan blade leading edge to the radiator core? It may be easier to push the fan forward with a spacer or a different clutch than it would be to get a longer shroud.

 

[DoubleDingo]

Wrong shroud

 

[guyindallas]

Thank you guys for confirming after market shroud. Very helpful as I decided on a solution for now.

I went and bought some aluminum sheet metal this morning…

I give you… “The Collar”

It is 104 in Austin today, temp gauge now does not go over the 210 mark, and the AC is blowing at 59 degrees in stopped traffic.

Happy.

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[guyindallas]

Oh also added a K&N intake.

 

[YakkoWarner]

Well thats one way to get it done - advantage being that its removable so if you do need to pull the shroud/rad/fan/pump/whatever in the future you've mad it easier to get the shroud out of the way first. Which will make doing the fan/clutch bolts a bazillion times easier.

 

[HotWheelsBurban]

Seems the shroud on classic industries does indeed look very different: https://www.classicindustries.com/product/1989/chevrolet/v3500/parts/t79434.html


I wonder if the current shroud on my truck was installed when the after market radiator came on... and wonder if a stock shroud will even fit now...

Dad used 1/4" bolts and nuts on the fan shroud halves, where the factory style has the push pins or whatever. Makes working on the front of the engine much easier.... On the GMT400/OBS trucks there are bolts and speed nuts on the halves, from the factory.

 

[guyindallas]

On another note: A/C in max mode seems to blow both floor vents and regular vents. Is this normal? Shouldn’t it only be the upper vents? Something stuck somewhere?