F250 Gear Box

Submitted: Tuesday, Dec 13, 2005 at 00:18
ThreadID: 122364 Views:7556 Replies:3 FollowUps:0
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G'day All,
A good friend of mine from Victoria has just purchased his 2nd F250.His 1st one was a V8 diesel manual and the new one is also a V8 diesel but fitted with a automatic gear box.
To improve fuel consumption he has fitted a Vendor Gear Box coupled to the F250 automatic transmission.
He is an expert mechanic and fitted the new box himself however he estimates it would cost approx.$5000 to have the job completed in a workshop.
The 2 benefits in fitting the Vendor Box in his opinion are improved fuel economy and a stronger transmission for towing heavy trailors.
He also changed the transmission oil to a synthetic called Castrol Trans Mac Z.
The person he received his information from is David of F Truck Accessories
Phone 0754957888 at Caboolture QLD.

C'ya Keith.
Bato Keith & Susan

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Reply By: The Hob - Tuesday, Dec 13, 2005 at 18:04

Tuesday, Dec 13, 2005 at 18:04

Is the unit you talk about similar to this one?


I notice that the article claims 23% increase in fuel economy but I guess that would be cruising down the highway. It appears to give an overdrive but what would that do for engine braking down a range where diesels shine over petrol?

Very interesting

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Reply By: Bato - Tuesday, Dec 13, 2005 at 23:38

Tuesday, Dec 13, 2005 at 23:38
G'day Alan,
I don't know the finer details of the Box however my understanding is it is an overdrive unit.If you need more info I would suggest you phone David at F Truck Accessories.

C'ya Keith.
Bato Keith & Susan

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Reply By: Bushtracker - Friday, Dec 16, 2005 at 00:26

Friday, Dec 16, 2005 at 00:26
I have been thinking about this one since the post came out on Monday.... And a word of CAUTION... Now I could be wrong, as I know nothing of this OD unit, nothing at all.
But, on the other hand, I owned my first F-250 in 1974, 31 YEARS AGO? (scary), and I have had significant research in all kinds of splitter boxes, and OD overdrive units, all the way up to the "Fairy" OD unit for Landcruisers.. I have done all kinds of research on this trying to get better fuel economy with big 4x4 rigs that I have had... Even converted my last F-350 to part time 4x4 with added Warn Lock out hubs, in 2002 for an attempt at better fuel economy.

The motivating factor was always fuel consumption since I went through the first real fuel crisis in 1974 or 5 ... I remember claiming if fuel ever got to a dollar I would get a horse... Well.... Anyway back to the topic. My research in the past came up with two problems, Torque and Wear. Yes the OD units did well running down the hiway, but not towing. The fuel economy yes did increase markedly, as the RPM dropped and you coasted along with the reserve torque. But before you make an expensive leap, I suggest you investigate #1 if the Bearings are up to a heavy towing job, as many of the OD units were not.. (Like almost all)... And second of all, it would be nice to see someone that has one try towing with it, as there will be a significant loss of power with the changed gear ratio. It is like putting on a super large set of tyres, on the top end when you engage the OD unit, taller gear in the box, sort of a 6th speed... However, it may not work for better fuel economy, as your foot might be in it too far pouring on the fuel. It would seem a real waste to get the Exxy unit, only to find that in fact it was not an appropriate gear ratio for towing, and in fact did not increase fuel economy.

If it was that easy, with the entire average Fleet fuel economy, Regulations and Mandates for Emission Control, required by the United States Government, then Ford would have made it an option.... At least I think so, because the F-Series is the Hog of the Fleet, and would drag down the averages. Soooooo, before you spend the big $, find someone that has it and test it towing. I am sure it is possible that it could increase fuel economy running empty, but not at all sure on the towing end; infact I would bet against it. My guess is that if it did it without excessive wear on the transmission, then Ford would already offer it. And yes, it would create heat on the Auto trans, and yes you would need TransMax Z synthetic oil to protect the trans from heat per my TIP # 29 on Auto Trans heavy towing in the Outback. And yes, if you were going the OD route, I would add another trans oil cooler...

Anyway, I could be wrong on this one, but I cannot see how Ford would have missed such an opportunity if it really worked, to improve their fleet fuel averages. My guess is there is some shortfall, and I will bet it is not appropriate for towing....

Kind Regards from the Ranger.

I might have owned Dodges and Fords and Chev trucks longer than anyone on the BOG. And I love the big 4x4s but fuel has always been a pain. Hence my research.
"The Last Stand In Open Country"

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