Rear end gearing

[mekanic-TC]

Just got a quote at $3K for gear change and $500 to pull, reinstall
Definitely not going to make this up on economy, but dropping the RPM's and postponing rebuild / preventing engine failure makes total $$ sense.
Plus our next trip is across Texas, New Mexico, Arizona and Nevada in August...definitely want to keep the heat load down and run the speed limit.

I did mine myself. cost me $307 for a set of 3.58 gears for my RR20-145 rear axle. paid a buddy of mine $100 to help me set them up right.
It took me about 20 mins to make a bracket so i could mount the center casting on a engine stand. (Makes it much easier that wrestling that thing on the ground) I bought my gears from Anderson bros in Portland, they are axle rebuilders. the gears I bought were even re parkerized.
My Ford had a set 5.29 gears in it when I bought it. Without a OD I was some where around 55 MPH for a top speed.

Mine has paid for its self. I'm sure of it.

 

[40's rock]

Well......live and learn.

Seems my 9 spd is a direct drive and I have 3:55 rearend. If we drop down to one step on rear gears, only drop 200 or so RPMs and not pu much top end.

So changing the trans to a 9 spd with overdrive...chart shows 1500 RPM @ 66mph....1800 rpm @ 80 mph

Economics don't make sense, never recoup costs vs fuel consumption, but much better on the engine long term than the current 2100 rpm @ 71 mph (and I can actually run the posted speed limit on open highway.)
Additional benefit will be everything from the clutch back will be inspected, PM'd and in perfect order.

 

[Bob86ZZ4]

So you're changing the transmission too?

 

[mekanic-TC]

I must admit i went from 41 tall tirs to 36.6 tall Low Pro tires at the same rime I did the gears.

Any chance you need tire and get taller ones??

 

[40's rock]

Installing a new (rebuilt) trans with OD. Pulled the rear gears to inspect and confirm ratio, 3.55's...everything back there is great
Luckily we went the trans route...clutch was almost dead and had a bent clutch shaft.

All in all hate to spend the money, but now everything from the engine back will be pulled, inspected and in top shape...AND I can actually run the speed limit on open interstate without killing the engine.

So the interior remodel is pushed back a little longer.

As for tire size...nothing larger will fit

 

[Bob86ZZ4]

Why not drop in lower numeric gears while you've got the rear end apart? Even with an o/d trans I think you could still go lower than 3.55 and drop the cruising rpm's even more.

 

[40's rock]

The rpm numbers look good with the current rear ratio and we did not want to over correct. Also the current gear set looked good, minimal wear.
I pull 15K and the coach weighs 21K filled and fueled (36K gross). So we will run it like it is and if we need more there is that possibility. Same $$ to swap later as now...and I spent all this month's lunch money already.

 

[40's rock]

Well, pu the Pirate ship this morning...WOW. I was definitely running a worn out clutch and trans!

Pedal is sweet, float shifts up and down...ran up to 81 MPH with motor to spare.

I went from driving a tractor to something that resembles a motorcoach...of course a wire disintegrated on the tach...always something.

She purrs at 70 vs the flat out turbo screaming I had before. WE will see what difference there is in MPG over the trip

 

[40's rock]

Loaded and running thru the mountains towing 24' trailer w/landcruiser...8 MPG. Not great, but so nice to downshift, especially going down steep two lane mountain switchbacks around Lake Tahoe.

Next, locking fuel caps. It appears someone relieved around 50 gals of diesel while the truck was parked at the trailhead for 3 days.

 

[Bob86ZZ4]

That's terrible. I hate that. I have locking covers on my fuel tank fillers. I have the kind as found here: Semi Truck Fuel Theft Caps - Locking Fuel Caps - Fuel Theft - Anti-Siphons - Diesel Fuel Caps

Mine look like this:

I like them.

 

[hot rod]

Rat bastard thieves. Hopefully the dumbasses pour it into their gasoline tanks for a little justice in the world.