96 Sahara 3126 fan blade needed

Covers engines and transmissions
stuplich@ymail.com
Posts: 1146
Joined: Mon Oct 28, 2019 8:51 am

Re: 96 Sahara 3126 fan blade needed

Post by stuplich@ymail.com »

Knollibe
Don't forget about the fan hub bearing.
Here’s a photo of the front of a Cat 3126 engine sans rad and fan..... from http://chaos.goblinbox.com/
Image
(The 6 bolt fan hub is near the center).
Mel
'96 Sahara 3530, mine since '01
250 hp 3126 Cat, MD3060 Allison
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: 96 Sahara 3126 fan blade needed

Post by TDJohn »

Dwayne,

It might be too late, but I emailed you some info regarding the fan. If you didn't getting it, check your spam folder.
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
Glenn
Posts: 11
Joined: Sun Oct 27, 2019 7:21 pm

Re: 96 Sahara 3126 fan blade needed

Post by Glenn »

I’ve just finished replacing my destroyed radiator fan while stranded in Pahrump NV. In the process I’ve discovered a few things that may be helpful to others in the future, so I’m posting this to pass the information along.

My fan was destroyed because the four 8mm bolts that attach the fan bearing assembly to the engine worked loose allowing the fan to shift off center far enough for the fan blades to contact the shroud. After the fan failure and subsequent overheat, I found the both upper bolts missing and both lower bolts loose and bent. I expect the loss of the last upper bolt may have caused a sudden shift in the fan position and blade contact with the shroud. A more gradual shift of the fan would have more likely resulted in the blades slowly cutting a deeper and deeper channel into the shroud. The drive belt was also broken, which would have stopped the fan and may have prevented further damage. Fortunately my shroud only suffered some minor chips and the CAC and radiator were undamaged. The fan, did not do so well, two blades missing completely and four others heavily damaged, with only one blade left mostly intact.

I have a CAT 3126 powered ’97 Continental. The radiator fan is/was an American Cooling Systems model 296256 28 inch diameter fan. This model fan seems to have been used on many of our CAT powered Safari rigs. Mine appears to have been an original installation, although I don’t know whether it was installed by CAT or Safari.

In ACS’s part numbering system the first three digits identify the fan model. The second three digits identify the hub design, including bolt hole circle size, number of mount bolts, and pilot hole size. Fan models can be supplied in various diameters, and the diameter is identified separately from the fan part number.

As others have discovered, ACS no longer supplies the model 296XXX fan with a 28 inch diameter, the maximum diameter available is 27 inches. After reviewing a number of possible alternative fan models on the ACS website, I sent an email to ACS Sales requesting guidance on either using the 27 inch 296XXX fan currently available or an alternate fan model. Bob Cooke at ACS Sales responded the same afternoon, and was very helpful and knowledgeable. After exchange of several emails, pictures, and a couple phone calls, Bob recommended switching to a model 444XXX, which is a 9 blade fan. Bob provided some fan performance graphs showing that the 27 inch 296XXX fan would provide considerably less air flow than the original 28 inch fan, and that assumes that the fan would be running in a 28 inch shroud. If operating in a 29 inch shroud intended for a 28 inch fan, performance would be even lower. The 444XXX model is a 9 blade fan rather than the original 7 blade 296XXX, and the performance chart for a 28 inch #444XXX fan shows increased air flow with a slightly lower power requirement than the original 28 inch 296XXX fan.

On my original 296256 fan, the second three digits designated a hub with six mount bolts on a 3.5 inch bolt circle and a “lemon shaped” pilot hole as pictured in an earlier post in this thread. I discussed this pilot hole with Bob Cooke, because it did not appear to me that either this pilot hole or the mount bolt holes would ensure the fan was centered on the fan mount when installed. Bob explained that this “lemon shaped” pilot hole is a special design used when transmitting high torque to the fan is required. It is used with a matching “lemon shaped” pilot. I did not have such a “lemon shaped” pilot for my fan to mount onto. I have a 2 inch circular fan mount, which I sent a picture of to Bob. Bob explained that I had a miss-match between the fan mount and the fan pilot hole, and since the “lemon shaped” pilot hole is considerable larger than 2 inches there was nothing to ensure the fan would be centered when mounted. These fans are surprisingly heavy, approximately 15 pounds, and if installed off center it will create considerable vibration. For my installation, what I needed a 2 inch round pilot hole in the fan hub. The ACS number to designate a 2 inch round pilot hole with six mount bolts on a 3.5 circle is 200, making Bob’s recommendation for a replacement fan a model 444200 28 inch diameter.

The next issue is that the ACS 444200 is only produced as a 32 inch diameter fan. To get a 28 inch diameter fan requires cutting down the blades of a 32 inch diameter fan and then rebalancing it. Fortunately this turns out to be a routine process performed by an ACS distributer, Superior Turbo & Injection, located in Detroit MI. Bob referred me to Josh Harsany at Superior Turbo & Injection through an email addressed to both of us, and Josh called me shortly afterward and was also very helpful. Superior Turbo & injection stocks a large supply of ACS fans, including the model 444200 that Bob recommended. They could have one cut down to 28 inches diameter, rebalanced, and shipped by the following day. Total price $110.84 plus shipping. I had the replacement fan in hand four days later via UPS Ground. Perfect fit, especially the pilot hole which fit snugly to the fan mount, ensuring the fan is centered.

While the fan was removed, I had my first opportunity to really inspect the forward side of the CAC for dirt and plugged air passages. Previously I’ve only inspected it by looking between the fan blades, and have attempted to clean it also working between the fan blades, and I believed I had it fairly clean. However, once the fan was actually removed I found that the CAC was approximately 25% plugged with dirt. With clear access, cleaning it with Dawn detergent and a high pressure nozzle wasn’t too difficult.

Bob Cooke at ACS can be contacted at bcooke@americancooling.com or 616-954-0280 x6108. Bob says he welcomes any inquiries.

Josh Harsany at Superior Turbo & Injection can be contacted at josh@superiorturbo.com or 313-842-4616 x921.

All the fan models, drawings, and hub designs, and specifications are available on the ACS website, www.ameriancooling.com.

Tips to others from my experience:

1. The four mount bolts for the fan bearing mount to the engine should be check for tightness periodically. They are difficult to see, with the heads sandwiched between the fan pulley and the engine. You can just barely fit an open end wrench onto the13mm bolt heads.
2. To inspect for dirt clogging the air passages of the CAC, and to clean the CAC if necessary, remove the fan. Removing the fan just isn’t that difficult, much easier and more effective than trying to work between the blades.
3. When the fan is removed, verify that you don’t have a miss-match of the fan pilot hole and the fan mount as I did. If you have the large “lemon shaped” pilot hole, and the smaller 2 inch round mount pilot, you have a miss-matched assembly and there is nothing to ensure that the fan is actually centered when mounted. An off center fan will result in unnecessary vibration. This vibration may have contributed to the loosening and loss of my fan bearing mounting bolts. If you find you have the “lemon shaped” fan pilot hole without the matching “Lemon shaped” fan mount, you should replace the fan. It would be a great time to upgrade to the model 444XXX fan.
4. Considering the very reasonable cost of the higher performance 9 blade ACS # 444XXX fan, you may want to consider upgrading even if you do have the correct, matching, fan pilot hole and mount.
Hopefully this information will help someone in the future.
Glenn B.
1997 Safari Continental 4006
CAT 3126 330
wolfe10
Posts: 222
Joined: Sun Oct 27, 2019 4:12 pm

Re: 96 Sahara 3126 fan blade needed

Post by wolfe10 »

Excellent write-up.

Thanks, Glenn.

Brett
Brett and Dianne Wolfe
Ex: 2003 Alpine 38'. Ex 1997 Safari Sahara. Ex 1993 Foretravel U240
Moderator, FMCA Forums 2009-2020
Chairman, FMCA Technical Advisory Committee 2011- 2020
Moderator, http://www.dieselrvclub.org/ (FMCA chapter) 2002-
Bilmac36
Posts: 75
Joined: Sun Oct 27, 2019 10:06 pm

Re: 96 Sahara 3126 fan blade needed

Post by Bilmac36 »

Glenn,
Repeat of Brett’s words. Well written write up. My ‘95 ‘Connie’ has the 8.3L Cummins, but if ever we move to a later year with a Cat I hope to recall your excellent recommendations cations.
Thanks,
Wm
r/Willie
'95 Safari Continental, Cummins 8.3L, Allison MD3060
05wingrider
Posts: 104
Joined: Sun Oct 27, 2019 7:26 pm
Location: Spokane, Washington

Re: 96 Sahara 3126 fan blade needed

Post by 05wingrider »

Glenn, thank you for a very informative response on this! I did a copy/paste so that I could print it out and put it in my "little" book of information and facts that I keep in my 96 (I say little because it started out a 1 inch binder and now is a full 3 inch one). Hopefully I never need a lot of the stuff that I've got in there, but if I do, almost every page of it has came from people like you sharing very important information. Again, thanks!
Duane
96 Sahara 30', 250hp Cat 3126
Allison 6spd MD-3060
2015 Jeep Cherokee Trailhawk "Toad"
Spokane WA
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