What kind of mpg gains have you guys seen from a free spin kit?

[ENafziger]

I've seen zero detectable mileage gain. Maybe 0. 012 mpg.

--Eric

 

[MLee]

You can't do a cable lock on the 3rd gens... no vacuum disconnect.

We realize that. I have been wondering ever since the new axles came out and the change from the CAD system, if you could interrupt the electronic circuit, to keep the front axle from engaging. I thought someone by now would have come up with a way to by-pass the system.

I interrupted the vac system on mine, it cost a couple bucks to do so, and I use it all the time. I do it cause I can.

We interrupt the start system, why not the 4wheel drive system?

 

[steved]

We realize that. I have been wondering ever since the new axles came out and the change from the CAD system, if you could interrupt the electronic circuit, to keep the front axle from engaging. I thought someone by now would have come up with a way to by-pass the system.
I interrupted the vac system on mine, it cost a couple bucks to do so, and I use it all the time. I do it cause I can.
We interrupt the start system, why not the 4wheel drive system?

???????

There is no disconnect at the 3rd gen front axle period. The only disconnect for the front driveline is the transfers. I don't follow your comment about the electronic deal??

The only thing the center axle disconnect does for a 2nd gen is to keep the ring and pinion from turning... the spiders still turn through and there is actually enough drag to spin the ring and pinion anyway. There have been kits out for years to manually actuated the cad... . both cable and electric over vacuum. Your still turning a bunch of stuff.

Have I mentioned how much I hate this new phone and its predictive typing... .

 

[AH64ID]

???????



There is no disconnect at the 3rd gen front axle period. The only disconnect for the front driveline is the transfers. I don't follow your comment about the electronic deal??

Exactly, its like the hubs are always locked.

 

[Mhannink]

yeah thats true i forgot this is a 3rd gen and that there is no other option then the hubs.



on the cad systems the ring and pinion dont turn, at least as far as i can tell. my driveline never spins in 2wd. the spiders do turn, that does take power but i dont know how much as it relates to mileage.

 

[steved]

The r&p turn because of parasitic drag.

 

[MLee]

Well I thought that the system that has the switch, not the stick could be done so the driveline, via the transfer case could be by-passed and not locked. Just a suggestion.

 

[steved]

if like older transfercases, the transfercase shift rails would also need modified to allow the shift rods to do low range without front axle engagement.

 

[Rascal]

I'm thinking about the free spin hubs. I got a dual rear wheel 3500. What companies has the hub kits for this truck and got the best prices? I heard most kits are for single rear wheel. Thanks for all help.

 

[RDeFayette]

free spin

Don't mean to poach threads,why did Dodge go away for lock out's in the first place?

Unit bearing is a cheaper as an assembly than component parts of a part time huib.

Less parts quicker assembly during production=less $$$

Back in the day when men were men (up to the late 70's early 80's) we didn't mind getting out in the mud/rain/snow to lock the hubs. Then the pretty boys started buying 4WD's and all the BS started. Autolocking hubs, Independent Front Susdpesion so it rides like a car, carpet, leather, abs, climate control, cruise control, automatic _ss wiper, and on and on... ... .....

At least back then on some trucks they gave us a choice manual/auto hubs!

Sorry I'm old school.

 

[Grey Wolf]

'93 was the last year for Dodge and a good unlocking hub

 

[CUMMINZ]

Without making any programming changes I am for sure seeing 2-3 mpg increases on my overhead. The steering is much better. As far as the conversion being worth the money I wished I would have made the changeover 4 years ago when I purchased the truck. One trip out west traveling over 6k miles @ a savings of 2mpg would go a long way in paying for the kit.

 

[RDeFayette]

hubs

I'm thinking about the free spin hubs. I got a dual rear wheel 3500. What companies has the hub kits for this truck and got the best prices? I heard most kits are for single rear wheel. Thanks for all help.

Dynatrac and spintec both make kits for duals.

 

[CUMMINZ]

Dynatrac and spintec both make kits for duals.

Don't forget Yukon.



With Dynatrac you have to make an addition purchase of hubs @ 300-400 bucks.

 

[WMoroni]

My answer for orignal question. ZERO, none, nondetectible. It would probaly be better on the highway but I'm off road and stop and go most of the time. It steers way better though. Would I do it again? No, not likely, alot of money for very little gain. Turns out I leave the hubs locked about 60% of the time anyway.

 

[SierraRam]

I have seen between a 1/2 a 1mpg gain, and it drive much nicer!

 

[retirednak]

I can't give any mpg gains since I haven't done my truck yet. But my trusty K5 Blazer plow truck came with auto hubs. They weren't even the kind to shift on the fly. No sir,you must have no wheel movement,one must be at a complete stop,engauge and go push snow. It took about a week before we went with free wheeling hubs and have never looked back. Also did the change over when my '90 GMC Burb went to work. I drove the wheel off the Burb and saw 1. 5-2 mpg increase when I had any road trips. Once winter hit,I turned the hubs and end of season unlocked them. I found a local dealer that sells the Yukon Hub kit and will be picking the kit up after the first of the month. They gave me a $1700 kit price and 5 hrs laber for the install. Can't wait to feel the driving difference and hope I'm lucky to see a 1. 5-2mpg increase in my mileage.

 

[Quilbilly brian]

I have had the Dynatrac system in my truck for over a year. I would say 1. 5mpg is what I achieved . I also did my ball joints and brakes and installed a steering box brace. the steering is 100% better. No wandering and very responsive. Yes this system is $$$$. But the payoff is the upgrade to longer lasting u joints and not putting wear on the Front Diff and axel. If you dont care about replacing your hubs every 30 to 50k with the sealed ones then by all means keep those crappy unpredictable un rebuild-able pieces of crap.

 

[Quilbilly brian]

How do you use 2wd low with out locking the hubs. . I dont think I understand how that works unless Its so obvious I am missing it...

 

[Motorhead]

How do you use 2wd low with out locking the hubs. . I dont think I understand how that works unless Its so obvious I am missing it...

You don't lock the hubs. You just put it into 4WD-LOW and you have 2WD-LOW.

This is excellent for backing a trailer with a stick shift... especially if you have an aftermarket clutch. Also easier on an automatic too.