Rovers North High Ratio Transfer

[Cutter]

TeriAnn,

I have thje 109 with the 2.6. Does this changes anything as far as the HR transfer. Is the one that Rovers North sells an Ashcroft?

Can a PTO be used with an overdrive such as roverdrive or the HR transfer like ike said? Les says NO.

Thanks

Stan

The HR transfer works well in the 2.6, at least in mine it does. The engine loses grunt in 4th but gets comfortably up to 55-60 cruising. FYI though mine is a euro 2.6 which different than the NADA. TeriAnn has a good breakdown of this on her site.

[leafsprung]

Ashcroft

Stan,
To clarify: The high ratio case is compatible with the PTO winches and other PTO accessories but you cannot use a HR case with overdrive. Nor can you use a overdrive with a PTO (except the rarer bottom PTO).


-Ike

[Firemanshort]

Not for nothing.... everything Teri Ann said plus the H/R gear set will be quieter than the overdrive. I realise that "quieter" is all relative, but neverhteless......

I had an O/D in my Stage One. Then I ditched that (well, it ditched me) and I swapped transfer gears to a higher set. I am VERY HAPPY with the quieter gear set - but I have a freshly rebuilt 3.5 V8 with a slightly taller cam in it.

[jumpmaster54]

Wow thats alot of info

TeriAnn,

I have thje 109 with the 2.6. Does this changes anything as far as the HR transfer. Is the one that Rovers North sells an Ashcroft?

Can a PTO be used with an overdrive such as roverdrive or the HR transfer like ike said? Les says NO.

Thanks

Stan

[TeriAnn]

The Engineers at Land Rover did a pretty good job of matching the gearing of a Series truck to the four cylinder engine so it can do the best job of pushing the truck under most conditions. When the early seventies gas crunch happened the overdrive came along adding gears allowing you to better be able to pick a gear that provides the best fuel economy. More often than not the best fuel economy was found by splitting the standard gears and not 4 over. The engine can not handle 4 over well in any adverse conditions. Especially with the heavier 109.

Stock form you have an effective overall gear ratio of 5.4:1. The transfercase high range is a 1.15:1 underdrive. Coupled to the stock 4.7:1 R&P you get 65 MPH @3686 RPM with 32 inch dia tyres.

Add a Fariy overdrive with its 0.78:1 high range to the stock gear ratio and you have an effective overall gear ratio of 4.2:1. You will reach 65 MPH @ 2867 RPM with 32 inch dia tyres. Assuming road conditions allow your engine to push that gear that fast.

Add a Roverdrive with its 0.8:1 high range to the stock gear ratio and you have an effective overall gear ratio of 4.32:1 You will reach 65 MPH @ 2948 RPM with 32 inch dia tyres

An Ashcroft high ratio kit converts your transfercase from a 1.15:1 underdrive to a 0.87:1 overdrive. changing the overall top gear ratio to 4.1:1 You will reach 65 MPH @ 2798 RPM with 32 inch dia tyres.

A stock transfercase with 3.54:1 R&P gives you an overall top gear ratio of 4.0:1. You will reach 65 MPH @ 2740 RPM

The higher the overall ratio the harder your engine has to work to push the gear. With a heavy 109 you may be at full throttle pushing the gear to 65 or with minor adversity you might not be able to push it that fast.

The big advantage of an overdrive is that you can split gears to find one that you engine can easily push without strain and with best fuel mileage. And the overdrives have a slightly lower ratio allowing your engine to push them easier.

The Ashcroft conversion and 3.54:1 R&P is like being stuck in a taller overdrive all the time. OK, in high range only with the Ashcroft and in all gears with the coiler R&P gears. The 2.25L engine has a real tough time pushing those ratios.

When you look at the numbers I think you will conclude that you are better off pairing an overdrive with a 2.25l engine. If the engine can't handle 4 overdrive where you are driving you can always take it out of overdrive. You can't do that with an Ashcroft conversion of a coiler R&P gear set.

Where the Ashcroft conversion shines is when you couple the transfercase with a more powerful engine. I have a Ford 5.0L V8 on my SII coupled with the Ashcroft converted transfercase and love the combination. But I would have hated it when I had a 2.25L engine.

[willincalgary]

I have an 88" with a very fresh 2.25 and a Roverdrive. No trouble driving around in overdrive all the time. It is a bit slow off the line but not that bad. I suspect with a 109 the highway might be a bit frustrating with just the high ratio.

[leafsprung]

Les, The ashcroft HR t case can be used with PTO accessories (except overdrive) . . . The ashcroft output gear (which is larger) does in fact have the PTO drive teeth.

-Ike

[jumpmaster54]

My Winch

My winch has the shaft that goes to the transfer. I guess I could always sell the winch on here. Its a Konig period winch and everything works. What is a fair price?

Stan

[Les Parker]

Please note if you fit the High Ratio Trans. box, the PTO option is gone !
The out put gear is changed from the standard one to a larger one, so PTO clutches CANNOT be fitted to the transfer box.
I hope your winch is crankshaft driven so you can opt for the High Ratio T. Box option.

[Cutter]

I have the HR TC on my 109, but I have a 6 cylinder. From my discussions, the always on nature of the High Ratio is a bit much for the 2.25 like I Leak Oil suggests. On mine it is great, and if you had a re-power I think it is a good alternative to an OD.

[I Leak Oil]

I don't hava HR transfer case but do have an OD. The ratios are about the same and I know I don't like driving around with the OD engaged unless it's on the highway. Too much of a dog(even more than usual!). My truck is an 88" with a 2.25 gasser.

[jumpmaster54]

I am finishing my 109 restore and I was thinking of an overdrive. I have a Konig winch on the front and if I go with a Fairey OD then I lose the winch option. Ig I go with the Rovers North High Ratio Transfer I can get both.

Does anyone have one of these high ratio transfers mounted? Does it give the top end as an OD? Please assist with any info.

Thanks

Stan