|Rear end ring and pinion swaps may work for smaller vehicles not towing anything.|
Okay, for folks looking into this upgrade take note. 1) I looked at swapping out the rear end to a lower ratio from 4.10 to something like 3.73 to get the highway cruising. Cost was about $900 for parts/ labor. However, the swap would also leave me with the risk of NOT being able to tow anything ever and also stressing the transmission on hill-climbing anyway due to the shift in rear end ratio... OK 2)installing a rebuilt 700R4 transmission. Cost? About $1600 to get the tranny, install and fitting it in with possible driveshaft alteration. Now, this also means my shifter would need alteration to deal with the 4 vs. 3 speed automatic. Likely would never be able to manually select 1st gear. Also, the 700R has a tendency to blow up on heavy duty installs. 3) install a Gear Vendor overdrive unit for about $3400. Holy cow! So it's double the most expensive option so what the heck??
|Swap a 4 speed and all is good, right? Maybe not if it's not rated for heavy duty...|
I'll tell you why this is not as crazy as it seems. OK, it is crazy but when you want a bit more for your money you look a bit closer.
What do you want to accomplish? Better mpg on the highway on long trips? A way to hill climb without frying your engine or tranny? When cruising you are not stressing out your engine at 3K rpms all day long. A better way to control shifting for just about any road condition without having to depend on the 3 speeds and kick-down alone? Something else to fiddle with and occupy your time while driving your rig? Come on, if you could drop a 5 or 6 speed manual into your old class A you would seriously consider it. I would if my arms were longer.....
|A Gear Vendors Unit may provide the right amount of control and highway cruise ability.|
I have looked into the Gear Vendor unit needed for our RV and it's not a motor home one due to the Chevy chassis we have. That saves a few hundred on the costs. The install involves taking off the transmission rear housing, installing an adapter along with the overdrive unit, then altering the driveshaft to fit. If you understand basic mechanics and have some help this can be done.
So, you've decided to go for it. What is the basic payback on this unit? Well, that depends on how much traveling you do and where. If you just look at mileage savings (they say this unit improves mpg by 23%) then from a fuel cost it would take the LH2 (getting 6.5mpg) getting close to 8 mpg and with the size fuel tank (64 gallons) that would figure to about 100 extra miles per tank. So, instead of going 416 miles on a full tank you could go 516 miles. With about $2.30 gallon you spend about $150 a tank full. So much MATH! If you took our trip to FL at 3200 miles total that's like 6 tanks vs. 7.7 tanks or about 1.7 tanks of gas for a total of $225. The more costly the gas, the quicker the payback. I spent an average of 2.60 gallon on the trip.
A unit like this would take about 12 trips to pay for itself just on gas savings alone. Seems like a crazy expense but when you look at the wear and tear on an engine that has to run at 3K rpm for a long trip without it then it's not so bad.
As with any upgrade the cost vs. the benefits may not be as easy to figure out and sometimes its really up to how you use your RV or plan to use it that my make that decision.
Happy and Safe RV'ing all!