109 Expedition rig build

[Mercedesrover]

Andre -

Those are great motors, aren't they. I can't wait to get this on the road and see how it pulls. The 616 in my 88" is perfect for that truck and has never let me down. I just keeps running and running. Funny to have an old Rover that you don't have to open the hood every time you want to go for a ride.

I agree that the overdrive might be nice but if push comes to shove I can always add one to it. I don't really think there is a great solution for overdrives for these trucks. The Fairy shifts nice but is noisy and doesn't last very long. The Roverdrive is quiet but shifts like a bus and runs VERY hot. I've got one of those in the 88" though, and it really helps with the low horsepower of that truck.

I've already got 4:56 e-lockers in my 88". Did it a few years ago and as far as I know was the first one to stuff them in a leafer housing. (I actually sell axles for that conversion as well as 24-spline axles for Series trucks.) I'm a little worried right now that the 4:10s are going to be a little tall for this truck. If it ends up they are, I'll switch them out with the 4:56 diffs in my 88" and rebuild these with 5:29s for that truck. Here's a picture of the front one for the 88" done and ready to go in the truck:



I wired them through the limit switches and have no trouble with them at all. The wires all run to a box on the tunnel with momentary switches.



There's a right up about the conversion on my site. http://www.seriestrek.com/toyotadiffs.html

Sorry Linus, I sold that engine and tranny months ago. It was a good running motor that went somewhere out west. Utah maybe? I forget.

jim

[dieselcruiserhead]

Yeah I agree about the aftermarket overdrives, no real nice options and I feel like they add a lot of clunk to the drivetrain too...

Neat to see those diffs in the Rover housings, very cool! I had the old 4.10, 4.56 philosophy but things changed a little with these low revving diesels that have their sweet spot under 2000 rpms. I'm running 35's with this current truck I'm building and thought is 4.1 should now be too tall too But I'm stuck with them with gears/diffs from a FZJ80. 8" high pinion front, 9" rear. They make slower (4.56, 4.88) but nothing faster than a 4.1. 3.73 would get me down to bout 1800-2000 rpms at cruising speed on the freeway in OD which would be perfect. With the 4.1s my mileage will go down and rpms up at the higher speeds, 70-75+, but not that big a deal...

I think 4.1 will be great and you'll be at 2500-3000 which should be perfect with ~31" tires that I imagine you'll run?

Cheers Jim and nice to see another Rover project from you! I love the old original Mercedes Rover!

[dieselcruiserhead]

Jim just checked out your site. I really dig those axles, very cool! When I had my '88 I was always worried I would break an axle out somewhere. Cheers and that is great. Are there good brake upgrades for Series axles these days?

[Loras BR]

A Mercedes-Toyota-Rover!!!

The perfect design and the perfect mechanic together...

Very nice plans!!!

Please, keep us updated!!!

[4Rescue]

Call me crazy but I'm keeping drum brakes. Don't know what all the fuss is about disks. All they've ever done for me is get stones stuck in the calipers and scream going down the road. My 88" is still on drums and it stops like a dream. Bleed them properly and keep them adjusted and I think they're fine.

Seriously, for all the great work you're doing, I know you're not... Well, seriously... All disk brakes have done is get rocks stuck in them??? Good brakes have as much to do with a rig as anything else. From your statement, I can only be led to believe that you are either:

A) My grandfather

or

B) My grandfather after falling down a flight of stairs...

Go 4wheel disks, this is not an oipinion thing...

Cheers and No Worries

Dave

[TeriAnn]

Call me crazy but I'm keeping drum brakes. Don't know what all the fuss is about disks. All they've ever done for me is get stones stuck in the calipers and scream going down the road. My 88" is still on drums and it stops like a dream. Bleed them properly and keep them adjusted and I think they're fine.

109 brakes are very different animals from 88 brakes. They work fine on the flats and quite good down hill, but ...

Those big brakes up front have both shoes set up as leading shoes. This means they brake very well in the forward direction and hardly at all in the rearwards direction. For practical purposes you have both front shoes and the leading shoe in the rear brake stopping you in the forward direction BUT only have the trailing shoe in the rear drum doing most all the stopping in the rearwards direction.

If you spend much time climbing 109s you will realize how poorly those 2 rear trailing shoes hold a nose up 109 in place. My total phobia of drop offs aside, the worst situation I can imagine for a stock brake 109 is having to come to a stop on a steep climb with a sharp turn and a cliff behind you.

What a front disc brake conversion will do is give your 109 front brakes that work just as well in the rear direction as in the front direction (like a stock brake 88).

I think stock 109 brakes are just fine for open field savanna type traveling but I suspect that you may have other things in mind. Go ahead and stay with the drums for a while. They work fine in most situations. If you need to come to a stop in a steep nose up situation go immediately into reverse gear then hold the vehicle in place. Then if it starts rolling rearwards you can have an in gear controlled rearwards descent.


Your rig, your choice. Might be best if you log hours on the stock brakes then determine if you actually need good rearward braking.

[Mercedesrover]

First of all, I don’t really think there is a good alternative disk brake conversion for the Series truck yet. I don’t even think Rocky Mountain is doing them anymore. At best these systems are proprietary and having trouble in the bush means contacting the maker and having parts shipped in at crazy overnight costs, if you can get ‘hold of them at all.

Second, the type of failure most likely to occur in a disc brake system will stop your truck dead. With the dust and mud and crud we’re subjecting them to a stuck piston is only a matter of time, and a stuck piston stops your truck. At best you’ve got a rebuild kit and a hone with you and you can rebuild them on the trail. The biggest problem you can have with a drum brake system is a leaky wheel cylinder, remedied with a cheap replacement part no larger than a roll of quarters that you’ve brought along, or at worst, replacing fluid until you’re able to find a replacement part. With my 88” I carry two wheel cylinders, which cover all four corners, on the 109 I’ll have to carry three. For the price and size of lunch I can carry the replacement parts for the most likely brake failure I will encounter.

We’ve also go the handbrake on these trucks that when adjusted and used properly can be a very effective tool off-roading. It frees up both feet to run the clutch and foot-feed and when working well is able to hold a fully laden truck either up hill or down.

If someone comes up with a disk system for these trucks that uses a slide on rotor and a common double piston, non-slide caliper I may consider it. Until then I’ll stick with my drums. Call me grandpa.

[Funrover]

AWSOME!!!! I can't wait till this is done!!!!

[gjackson]

Jim,

Very cool project! I'm very interested to know how the Merc will pull that 109.

cheers

[TeriAnn]

First of all, I don’t really think there is a good alternative disk brake conversion for the Series truck yet. I don’t even think Rocky Mountain is doing them anymore.

I believe they do but they have never been on the Rocky Mountain web site. Rocky Mountain is just a distributor of the conversion.

At best these systems are proprietary and having trouble in the bush means contacting the maker and having parts shipped in at crazy overnight costs, if you can get ‘hold of them at all.

Paul Heystee's conversion is based upon the vented disc brakes that comes standard on the Spanish built Santana PS-10. The PS-10 is basically a Land Rover clone so is in the same weight range as a Series LR. This is a 2 piston vented disk brake system. The Santana PS-10 brake components are the same as used on the Mercedes MB100 van which was never imported into the United States. so yes you would have to import parts from Europe.

The ones on my Land Rover are made by Torrel Industries. This 11 inch vented brake kit uses common (North America) AC Delco dual piston calipers, pads and rubber hoses. The GM rotor does require machining to fit. So it does have a custom consumable. I can probably source new calipers, pads and hoses off the shelf in any North American auto parts store. Rotors would take more time.

Timm Cooper's conversion is back on the market with a new batch of castings. Timm's conversion uses standard off the shelf Defender/ Range Rover Classic disk brake calipers and rotors. These are 11-3/4 inch dia rotors with 4 piston calipers.

Zeus will not sell their conversion to anyone with a US address. It is a 4 piston vented system and other than that I really don't know anything about them.

I will not insinuate that you are making a poor choice, just a different choice than I did. We all drive different rigs different places in different ways and have different reliability & safety concerns. There are many very good choices, all with very good reasons. I think you do dynamite component engineering and am following your 617 conversion with awe.

Best of luck on your project!