Freightliner ambulance conversion project.

[Ozrockrat]

Hi Scooter

I wouldn't be concerned about getting stuck. There are a couple of thousand people itching to get their recovery gear out. And our buddy Wolf with his deuce 1/2 had a great time pulling out everything up to a class A motor home.
With your tranny temp. Have you checked all the wiring and maybe even shot the cooler lines with an infrared thermometer. 210 is not obscene for the World Series Allisons 3000 and 4000 series but if I remember you had an earlier tranny and I don't have any experience with them. If they are anything like the 3060 the internal "filter" is actually more like a mesh screen and really only needs cleaning and replacing when they are overhauled.

I like those clean and shiny rims but I don't envy the pain in the wallet putting tires on them.

Have a great time camping and remember if you do come to Expo we will not leave you stranded.

 

[LandCruiserPhil]

Glad to hear the trans is complete and working correctly.

 

[rossvtaylor]

Hey Ozrockrat,

You've currently got a 4.33 rear end, right? Are you going to change that or is it working okay? I'm asking in advance of our tire size change. We're wondering what to expect, and plan for, once we get those on.

Thanks and it was great to meet your family at the Expo!

Ross

 

[Ozrockrat]

Hey Ozrockrat,

You've currently got a 4.33 rear end, right? Are you going to change that or is it working okay? I'm asking in advance of our tire size change.

Ross

I will be changing my final drive ratios. But remember I am looking at cruising at 65 with no real requirement for over 70 (not much interstate work and I need the lower grunt for the more adventurous tracks). Plus my change from 29" to 43" was a bloody big step. You will be going from 33" to approx 39" (depending on the final tire selection) and have the 8.3 Cummins over my mini me 5.9 plus currently 6 speed over my 5 speed (did I even mention being jealous :drool: )

The 8.3 should pull the 4.33 gearing OK with non MPT tires you should be able to cruise at 75. But I do know where there is an RS 17-145 with 4.88 and a locker. I think you may have to change axle shafts (RS 17-144 has 41 splines and the RS 17-145 has 39 splines). But the selective lockers on the Mertior/Rockwell axles are impressive. Hit the air switch (or solenoid) and they come in with an impressive thunk and totally lockup the axle. These are the ones they use on dump trucks etc so they would be very reliable (never had any luck finding one for mine).

If you feed your info into this calculator it will give you an idea of the ratio/speed/rpm changes. http://www.grimmjeeper.com/gears.html

For reference the gear ratios on the Allison MD3060 are:
First - 3.49 : 1
Second - 1.86 : 1
Third - 1.41 : 1
Fourth - 1.00 : 1
Fifth - 0.75 : 1
Sixth - 0.65 : 1
Reverse - -5.03 : 1

 

[Ozrockrat]

This is running the calculations on my truck with the planned diff change. You will notice that if I go for a 6 speed instead of the 5 speed it will give very little net effect on the final rpm v speed ( a little lower rpm at cruising speed) but will give me an advantage in the lower gears. Click on the image to read anything.

 

[MNtal]

Consider me a +1 for sound deadening if they will do an expo buy.

 

[scooter421]

I figured there would be plenty of good folks willing to help out if I had trouble. I'm just testing my confidence with my ambo little by little! Very confident I will be there next year.

I have not tried checking the lines with the infrared thermometer and that is an excellent idea. I may do that this weekend to verify. What I learned on my camping trip....it seems on relatively flat terrain and/or at idle the trans runs around an estimated 180-195F and 0-55 mph. Climbing medium hills or long hills at about 45 MPH it runs around 200-210F and climbing up Mt. Ord headed to the RIM territory (Chevelon Canyon Lake) it was showing 220F at 35 MPH and held steady. 35 MPH is all it can realistically do going up that hill. I made it up and back with no issues; albeit, much slower than I would prefer but I suppose it did well.

So, camping was a success! Thank you...

Yes, the pain in the wallet is coming very soon! I've got the tires lined up and just gotta get em done!

 

[rossvtaylor]

...I do know where there is an RS 17-145 with 4.88 and a locker. I think you may have to change axle shafts (RS 17-144 has 41 splines and the RS 17-145 has 39 splines). But the selective lockers on the Mertior/Rockwell axles are impressive. Hit the air switch (or solenoid) and they come in with an impressive thunk and totally lockup the axle. These are the ones they use on dump trucks etc so they would be very reliable (never had any luck finding one for mine).

Excellent info, as always - even with the drool. Thanks, we did well I think. But you've got a beastly rig and ours aspires to look more like yours. I can't help with the engine or tranny programming, but there are cruise control options you can add for under $200.

As far as the locker goes, that sounds fantastic. But, we've not budgeted for an axle replacement. Between the lifting and the tires and new shocks, we're going to be done with that part for a while. We've got painting and graphics to do, first. But... if it's cheap enough then maybe it could be done when we're lifting it anyway? Now it's my turn to drool...

If we had limited slip, I might just leave it as is. I don't even know if we do, though. I see that Meritor has it as an option, but I haven't pulled the number off our axle/differential to check yet. Being able to lock it up, though, would be nice indeed.

 

[Ozrockrat]

Here I go hijacking my own thread

But if you check the Allison installation guide it will tell you which way the cooler lines need to be connected. I think it needs to run in reverse to the coolant flow. Not sure it would make that much difference. Also the with later Allisons 200 is fine and 225 for extended periods are where the problems are. (Higher with a retarder). If you are running the recommended synthetic in the 3000 series 210 - 220 should never be a problem.

 

[Ozrockrat]

Oh look color matching stud tension indicators. How pimped out can you get.

Seriously though these should be on every medium duty rig. For about $30 you can have an easy way to see if your wheel studs are loosening off when you do your pre start check (you do a pre start check don't you???)

 

[Ozrockrat]

Air conditioning. After 3 years (and we live in Phoenix). I finally decided to take a look at the air conditioning. A couple of hours later and it is working (not the most efficient AC around).

2 things I found out.
1- the fuse/relay panel diagram I have been using for years was incomplete.
2- on my rig there was an interlock between the standard cab AC controls and something to do with the box. I have no idea of what it is. There was no indication of it in either the Freightliner wiring diagrams or the ones for the box that came with the Ambo. So I just bypassed it and went back to standard Freightliner for the cab. I do wonder if it had something to do with the load control as cab AC would probably not be considered essential service.

 

[rossvtaylor]

Air conditioning. After 3 years (and we live in Phoenix). I finally decided to take a look at the air conditioning. A couple of hours later and it is working (not the most efficient AC around).

Yay! Glad you have cab AC now. Ours works there, but still no box cooling yet. As with your observation, our cab AC isn't stellar. Try something, though... Put your hand on the dash panel below the AC/heater control panel. Is it ice cold there? Mine is. I don't get great volume out of the ducts, but it seems to be blowing hard on the back of the panel. I haven't opened it up, yet, but I suspect I'll find decomposed foam or a loose duct joint. I've read that's a common thing in rigs our age.

 

[Bikersmurf]

Oh look color matching stud tension indicators. How pimped out can you get.

Seriously though these should be on every medium duty rig. For about $30 you can have an easy way to see if your wheel studs are loosening off when you do your pre start check (you do a pre start check don't you???)

X2 These helped me to spot nuts that were coming loose on my E350 Ambo... scary thing to find. A Very good reason to do a pretrip inspection once a day.

 

[AMBOT]

X2 These helped me to spot nuts that were coming loose on my E350 Ambo... scary thing to find. A Very good reason to do a pretrip inspection once a day.

I lost a rear wheel due to loose studs, thankfully it was a dually and lost only one tire. The result was catastrophic, to the Hyundai it hit, thankfully no one was injured.

GET THESE or at a minimum take a sharpee and mark the studs along some reference point for visual inspection.

 

[guidolyons]

^^^ Also used in aviation known as torque mark or slippage mark..or bird ********

http://www.amazon.com/Tamper-Proof-Torque-Mark-Red/dp/B007ID3SLK




I like those stud tension flags, too. A bit cleaner and not as messy as a torque mark.

Oz- are those the Torque-tight flags? http://torque-tight.com/