Modern Autobox for Classic Cars?
Discussion
Looking at various classic saloons from the 60's and 70's I'm struck by the number of cars that are "hampered" by the old three-speed autoboxes of the period.
Not everyone wants to fit a manual gearbox and I think most Jags, Jensens, Rovers and the like somehow suit the autobox style of driving.
Question is - can a more modern five or six speed box be adapted to these old classics ? I realise all modern(ish) boxes rely on several electronic inputs, but surely these can be simulated or by-passed.
Has anyone carried out such a conversion ?
Surely there is a market for this - imagine an Interceptor, XJ12 or P5B Rover with a five speed autobox. I think it would be a revelation.
Not everyone wants to fit a manual gearbox and I think most Jags, Jensens, Rovers and the like somehow suit the autobox style of driving.
Question is - can a more modern five or six speed box be adapted to these old classics ? I realise all modern(ish) boxes rely on several electronic inputs, but surely these can be simulated or by-passed.
Has anyone carried out such a conversion ?
Surely there is a market for this - imagine an Interceptor, XJ12 or P5B Rover with a five speed autobox. I think it would be a revelation.
Pistom said:
I must agree with this but don't know how easy it would be to do. I imagine that if you go for a modern box you may as well go for a modern engine. You then enter a new level of complexity.
It may sound crazy but I would never consider putting a modern engine in a classic but I wouldn't have any problem fitting a modern gearbox.My Corvette originally had a manual 4 speed Muncie gearbox, the revs needed on the motorway made long haul drives quite wearing. During the rebuild I took the opportunity to fit a 6 speed Tremec (5 close ratios and an overdrive 6th). Motorway cruising is now done at a very relaxed 1200 rpm, additionally I was able to fit a lower (4:11) diff which improved the acceleration, a real win/win mod.
G
G
Older 3 speed automatic gearboxes are perfectly suited to older lower revving large capacity V8 powered cars with a wide torque band. A later three speed auto with lock-up overdrive can with some work to prop shaft and cross-members be retro fitted and drop a 2500 rpm cruise down to 1800 rpm. The very latest ZF 8 speed auto gearbox is proving to be the benchmark transmission of all time (I'm running a BMW 120D with one of these and it really is very good) - I know they are being used on bigger Beemers and some Porsches - whether it will handle the torque of a V8 is another matter - and I guess what is the price going to be?
mph said:
Looking at various classic saloons from the 60's and 70's I'm struck by the number of cars that are "hampered" by the old three-speed autoboxes of the period.
Not everyone wants to fit a manual gearbox and I think most Jags, Jensens, Rovers and the like somehow suit the autobox style of driving.
Question is - can a more modern five or six speed box be adapted to these old classics ? I realise all modern(ish) boxes rely on several electronic inputs, but surely these can be simulated or by-passed.
Has anyone carried out such a conversion ?
Surely there is a market for this - imagine an Interceptor, XJ12 or P5B Rover with a five speed autobox. I think it would be a revelation.
Depends really. The really modern (8 speed ZF) box is completely electronic and it needs an ECU to work, probably talking to the engine ECU too, so you are limited to gearboxes that control themselves. There are late model older style transmissions that will be 4 plus overdrive that would do the jobs better though.Not everyone wants to fit a manual gearbox and I think most Jags, Jensens, Rovers and the like somehow suit the autobox style of driving.
Question is - can a more modern five or six speed box be adapted to these old classics ? I realise all modern(ish) boxes rely on several electronic inputs, but surely these can be simulated or by-passed.
Has anyone carried out such a conversion ?
Surely there is a market for this - imagine an Interceptor, XJ12 or P5B Rover with a five speed autobox. I think it would be a revelation.
I can't find a link for them but there was a German engineering firm bolting in the V8 & autobox from the W126 SEC coupes into fifties W111 220 Seb Coupe's - I found an example here:
http://www.flickr.com/photos/chromjuwelen/51240985...
http://www.flickr.com/photos/chromjuwelen/51240985...
The AW 03-71L box fitted to late 80s Vauxhall Senators should be easily modified. Its a 4 speed with lock up in fourth. It has an ECU but the major functions of the box are mechanical. All the ECU does is control sports and winter modes, and the speed at which top will lock up - a switch can be installed instead of the speed sensor it uses originally.
One of my buddies 'upgraded' the autobox on his 454 Vette to a three plus o/d GM box from Bow Tie Overdrives in the 'States. They source them from an 80's Camaro or similar, change internal ratios etc, supply uprated converter and cross-member plus propshaft. Ratio's plus o/d lock-up are great - seem to recall it cruises at 1400 rpm or so at 70mph and has really snappy performance with modded ratio's.
Nothing wrong with this at all and if you're actually going to use your car its a very good idea. Early automatics are woefully inefficient for the most part, parts for them can be scarce and they are generally 2 (in the case of my 54 Ford functionally 2) or 3 speeders. The trick is to use a non-electronically controlled one. I've got a 1990s Ford "AOD" for my 54 Ford that needs to go in.
Swapping a 1950s vintage Fordomatic with an AOD will give me 12-15 extra HP at the wheels, improve mileage and bring RPMs way down on the highway. Plus the Fordomatic really only uses 2nd and 3rd, first only works of you select low.
A company called Bendsen's makes a transmission adapter for the Buick 215 V8 to use a Chevrolet transmission, assuming that the bell housing pattern on a Rover V8 is the same this would allow you to use something like a 700R4 behind a Rover V8. Not cheap but their stuff is VERY well made.
Swapping a 1950s vintage Fordomatic with an AOD will give me 12-15 extra HP at the wheels, improve mileage and bring RPMs way down on the highway. Plus the Fordomatic really only uses 2nd and 3rd, first only works of you select low.
A company called Bendsen's makes a transmission adapter for the Buick 215 V8 to use a Chevrolet transmission, assuming that the bell housing pattern on a Rover V8 is the same this would allow you to use something like a 700R4 behind a Rover V8. Not cheap but their stuff is VERY well made.
Certainly would agree that the ZF4HP22 box is a good improvement for most three speeds. i am going the other way with My XJS V12 Le Mans and putting a six speed manual in it - one that is only overdriven in sixth so as to not destroy the overall gearing.
I would also love to do a Range Rover classic with a 3.0TDV6 and six speed auto. i'm sure i would need to use the entire wiring loom and instruments too though.
I would also love to do a Range Rover classic with a 3.0TDV6 and six speed auto. i'm sure i would need to use the entire wiring loom and instruments too though.
mph said:
I could only find a more conventional four speed lock-up auto gearbox when I searched. Do you know which specialists are offering the conversion and which box they use ?
A couple of fellas in the club have fitted the four speed Chrysler box but the conversion I am referring to is the ZF 5-speed, although I do not know part numbers, etc.Cropredy Bridge Garage market it and also I believe, Duncan Watts Transmissions.
SV8Predator said:
A couple of fellas in the club have fitted the four speed Chrysler box but the conversion I am referring to is the ZF 5-speed, although I do not know part numbers, etc.
Cropredy Bridge Garage market it and also I believe, Duncan Watts Transmissions.
That will no doubt be the A518. I did look into that a while ago, but discounted it when I realised that a 6 speed "Tiptronic" type box was possible using an A727 base. Six speed, fully auto or fully manual...Perfect!Cropredy Bridge Garage market it and also I believe, Duncan Watts Transmissions.
Since 2002, no Range rovers were made without an autobox!
And the latest Discovery can have the NINE speed ZF 9HP!
http://www.zf.com/corporate/en_de/products/innovat...
Is that the way you wnant to go?
John
And the latest Discovery can have the NINE speed ZF 9HP!
http://www.zf.com/corporate/en_de/products/innovat...
Is that the way you wnant to go?
John
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