SERIES overdrive with auto box?

[seriesly]

ive got a fairy overdrive i want to fit to my series 3

its out of a series 2a

its got a fjord 4.1/c4 auto conversion

i have to switch the motor off to change h/l range.

my questions
1. does an overdrive need the clutch depressed to be engaged?

2. would it damage the overdrive to start from standing with an auto box?

:)

[Blknight.aus]

depends on which overdrive, generally Ive found double clutching helps them no end when it comes to shifting so assuming that your transmission doesnt do neutral real well then yes you would have to stop to shift.

and no, providing you arent to hard on the right boot when you take off taking off in either ratio wont hurt the overdrive

[JDNSW]

The Fairey overdrive has got synchromesh, and at least on the one I have, it works very well. If your synchromesh is working it would handle changing with the transmission in neutral without any problems, and probably even in gear provided it is not driving or overrun. If the overdrive is under load when you try to change, it will be almost impossible to move the lever without forcing it, and from neutral to in gear will simply not go in if there is too much speed difference, so there is little chance of doing anything other than a bit of wear on the synchromesh trying it.

The Fairey overdrive is rather fragile, and has a small oil reservoir, so I would be rather cautious about using it from a standstill, particularly with the larger engine, even with an auto - the lack of shock loading will probably stop you from breaking anything, but if, for example, starting off up a steep hill or heavily loaded, or accelerating rapidly to high speed, is likely to give relatively rapid wear and is likely to overheat the overdrive.

John

[fraser130]

With a little practice you should be able to engage it by matching the engine speed to your road speed in top gear, and it will just slide in.

Fraser

[isuzurover]

If you have a 4.1L engine and an auto, I would fit 4.11 diffs instead of an overdrive.

[PAT303]

If you have a 4.1L engine and an auto, I would fit 4.11 diffs instead of an overdrive.

My choice too.It would be a hell of a lot quieter to boot. Pat

[Leo109]

If you have a 4.1L engine and an auto, I would fit 4.11 diffs instead of an overdrive.

Or even better, IMHO, a set of high-speed transfer case gears. 28% taller high range gearing but standard low range gearing is retained. Going to 4.11 from 4.7 diff ratios is only a 14% taller ratio and applies to low range as well. If buying it all new, I'd think the HS transfer gears would be a lot cheaper than two 4.11 CW&P sets?

Made my SIII/GMH 202 much nicer to drive on the highway - about 1000 less rpm @100km/h.
Ian

[isuzurover]

but standard low range gearing is retained.

All true, except for this bit.

Low range is increased slightly with the HRTC. This also precludes you from fitting the 2.89:1 low range gears from a suffix B SIIA. Which would more than compensate for 4.11s.

Also, depending on the mods which have been done to the t-case to fit the auto, custom work may need to be done which would increase the costs. The HRTC conversion requires the intermediate shaft hole in the t-case housing to be welded up and a new hole machined. If the t-case or the input gear are custom (due to the C4 conversion), then you will need to ship them off to whoever still does this conversion (ashcroft???) and get them modified.

[jimbo110]

I don't know about yours, but my auto conversion comes out through the rear of the transfer case in the position of the PTO/overdrive position, so I can't fit anything to the rear of the transfer case.:(

[seriesly]

thanks for all the replies.

i will check out the hrtc

the ford 6 chews so much lpg its not funny

[LandyAndy]

Perhaps the LPG is running too rich if its chewing it.
The young bloke at work got an extra 100km out of the gas on his rangie by learning how to tune it.
You can tell if its too rich,get somebody to follow you if it really smels strong you are putting unburnt LPG out of the exhaust.
Google LPG tuning and you will get the gist of how it all works,it isnt rocket science.
Mark everything with a chemi pen before you adjust anything and write it down as you do it.I bet you get it to drive better and use less,I did on my last Series Landy(202 LPG)
GOODLUCK
Andrew