Jump to content

Overdrive on 300Tdi 110 CSW


Recommended Posts

As you will have seen from my 'Snowchains' thread, I am off to the Pyrenees in February and will probably cover 3000 miles or so in the week, including the long hauls up and down, most of which will be on the Autoroutes.

I am seriously considering fitting a GKN Overdrive unit to improve fuel economy and destress the engine (and my ears!).

I have read the 'Overdrive' thread in the technical archive and note that the author of that has a TD5 90 rather than a 300Tdi 110. Having spoken about it in the past to the service manager at the garage where I used to have the thing maintained, I was advised to go down the high ratio transfer gears route rather than fit an overdrive.

I am a little reluctant to do that as I will lose some of the extra urge at lower speeds that I gained from having Van Aaken tweak the fuelling a few years back. O/D seems to provide the best of both worlds, and I am familiar with the operation of that system, having owned and driven many overdrive equipped Triumph cars over the last 24 years.

Has anyone on here fitted the GKN unit to a 300Tdi (I know you have one on your 200 Ralph....) and what are the drawbacks likely to be (if any)?

Many thanks

Link to comment
Share on other sites

I know someone who has a GKN overdrive on his 300 tdi 110, he's toured thousands of miles of Africa and maintains that the GKN is the best thing on his vehicle, not because of fuel saving, but because of the drop in noise and vibration at cruising speeds.

You reading this Mike?

Link to comment
Share on other sites

Ok, not on a 300Tdi, but had one on the 110 crew cab TD5, was excellent, to the extent, that i will fit one to whatever i have, for the trip down to spain etc, next May, makes 5th gear so much more relaxed !

Have you found a good supplier yet ???

Link to comment
Share on other sites

I know someone who has a GKN overdrive on his 300 tdi 110, he's toured thousands of miles of Africa and maintains that the GKN is the best thing on his vehicle, not because of fuel saving, but because of the drop in noise and vibration at cruising speeds.

You reading this Mike?

You called Luke. :lol:

Yes I have one fitted to my 300Tdi station wagon. I love it.I wouldn't want to go back to being without it. Noise wise it's superb.MPG wise I can't tell you as I fitted the roof rack at the same time.

What I can tell you is.....

I have an Alli-Sport up-rated intercooler and Alli-Sport adjusted the pump.I also removed the exhaust center box.

Both gave me a lot more low down torque.

I can now travel in a 30MPH limit in 5th gear 1,100 revs at 30MPH.

I averaged 26MPG on our last trip. The Defender was consistantly laden to over 3.4TONNES. Jerry cans on the roof and a roof box.The winds in Botswana are strong I might add.

The overdrive only operates over 30MPH.

I use mine as a 6th gear.

Overdrive top is higher than 5th gear. So it's not a splitter in that sense.

HTH

mike FOAK

Knickers

I can cause trouble in an empty house !!!

Link to comment
Share on other sites

Thanks for the info. I think it may be the right way to go although I do appreciate that it is an expensive option.

I have had a brief look on the net to try and get some prices. They range from £800 + VAT up to £1150 + VAT at the moment :o

Anyone got any suggestions as to the cheapest place to source one? I hope that my usual trusty mechanic would be able to fit it for me.... :P

Link to comment
Share on other sites

Thanks for the info. I think it may be the right way to go although I do appreciate that it is an expensive option.

I have had a brief look on the net to try and get some prices. They range from £800 + VAT up to £1150 + VAT at the moment :o

Anyone got any suggestions as to the cheapest place to source one? I hope that my usual trusty mechanic would be able to fit it for me.... :P

Devon 4x4

mike FOAK

Knickers

I can cause trouble in an empty house !!!

Link to comment
Share on other sites

I have a 300TDi (fitted with a 2.8TGV) with a rocky mountain overdrive.

It's all manual in terms of lever engagement whereas the GKN is via solenoid.

Mine works in all gears low and high therefore 20 forward gear possibilities :o

As Mike and others comment noise is reduced, circa 500-1000 revs on mine.

My engine has loads of low down torque so the OD really does help stretch it's legs.

Can't comment about fuel consumption as it was fitted at the same time as the TGV.

John

Link to comment
Share on other sites

The Rocky Mountain OD is approx £850 so not much of a saving in relation to the GKN unit.

Though in some respects it is simpler, it also runs on the same oil supply as the transfer box so no need to worry about seal failure causing contamination of oil either way.

the only drawback I could see to fitting the Rocky Mountain OD was that the gearstick for engaging is located on the passenger footwell side of the tunnel(assuming a RHD truck.) But I am sure that with a bit of thought it could be relocated to the other side.

I have a GKN on mine and have put about 50,000 miles on it thus far. The only problem I have had so far is a failure of the speed sensor.

But having had an OD fitted I would not willingly go back to being without, it makes such a difference. I drive the length of France quite regularly and the ability to sit there at 70MPH all day (no traffic) is a great help. Under these conditions and reasonably well laden, the truck returns between 33 and 36mpg But it is the ability to hold a conversation at normal conversational volume, in a 110 hardtop, that is just wonderful. It also means that I can realistically expect to drive 500 miles in an 8 hour day and still be reasonably fresh at the end of it

Link to comment
Share on other sites

Guest diesel_jim

Has anyone here got a 110 with a 1.2:1 transfer box instead?

any comments? (i've got a 110, and a 1.2:1 box in the garage..... :unsure: )

standard tune at the moment. but when/if i actually own it outright i'll get it tweaked somewhat.

Link to comment
Share on other sites

Just found this info, the Paynes unit maybe worth investigatiing :)

While googling 'overdrive' yesterday I came across this site and e-mailed the owner of the company. He replied within minutes, but unfortunately the Land Rover overdrive he has developed is not yet production ready. I am still waiting for a response to my offer to do some 'beta-testing' of his system for him!

Looks like I may have to go with the GKN unit from Devon 4x4. Pity, 'cos I would like to have supported a local(ish) independent company.

Link to comment
Share on other sites

Guest diesel_jim

FJ Payne is a really friendly (well, by email anyway) company, i've had a few email chit-chat's with Tim Payne there, they were developing a 2.8Tdi a few years back (before the international 2.8 came in the scene), by overboring the cylinders and doing some head work.

i think they had some quite good results.

Link to comment
Share on other sites

I was also looking to increase the cruising speed of my 110 CSW and had a quote of £345 + exchange old unit for a recon LT230 1:222 ratio transfer box from these people www.freewebs.com/tmtransmissions/ which is a bit more competitive than a GKN but perhaps not so flexible. You pays your money and takes your choice. Unfortunately for me living in France, the cost of shipping the old unit back to the UK makes the whole deal cost about 1,000EUR so not really worth it.

Link to comment
Share on other sites

i spoke to Tim Payne at the time of deciding on overdrives for mine and he was working on it then, that was a little while ago (2000?) i did see a prototype at one of the shows but went for the GKN in the end, its now done 60k odd miles and going strong, less the speed sensor which i think is about to give up the ghost. i still stand by comments on my tech thread.

Tony - def worth it for the noise benefit over the years. mine has paid for its self in fuel economy saving (but only just!)

Link to comment
Share on other sites

gearknob/switch works just great just where it needs to be. GKN will sell you a complete replacement gearknob/switch [GKN part numbers-- 1. body section 119411/00/00 & 2. gear knob lid complete with switch & wiring connector 119416/00/00 ] assembly wiring you'll have to sort to suit your system, the switch is just a circular on/off rocker type with a red led to indicate when the OD is engaged but speed to low [below 30mph] & as a elect system check when ignition switched on. phone GKN on 0121 313 1661 ask for sales or e.mail on sales@gkndriveline.co.uk

Link to comment
Share on other sites

Guest diesel_jim
gearknob/switch works just great just where it needs to be. GKN will sell you a complete replacement gearknob/switch [GKN part numbers-- 1. body section 119411/00/00 & 2. gear knob lid complete with switch & wiring connector 119416/00/00 ] assembly wiring you'll have to sort to suit your system, the switch is just a circular on/off rocker type with a red led to indicate when the OD is

I suppose if you've not got an overdrive, you could use one of these gearsticks to operate your passenger ejector seat? :D:D

Link to comment
Share on other sites

gearknob/switch works just great just where it needs to be. GKN will sell you a complete replacement gearknob/switch [GKN part numbers-- 1. body section 119411/00/00 & 2. gear knob lid complete with switch & wiring connector 119416/00/00 ] assembly wiring you'll have to sort to suit your system, the switch is just a circular on/off rocker type with a red led to indicate when the OD is engaged but speed to low [below 30mph] & as a elect system check when ignition switched on. phone GKN on 0121 313 1661 ask for sales or e.mail on sales@gkndriveline.co.uk

Thanks! I'll give them a call today.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy