Has anyone seen a successful conversion to a 5 speed automatic transmission with a lock up torque converter? I'm thinking that would be easier, cheaper, and more in character than the manual trans route.

 

outside of mazdas 5 speed. good luck with that one. just go 4 speeed 4l60e

EDIT: 4l80e is a 6 speed auto.

 

The Mercedes 722.6 is a very good 5 speed auto, has lockup from 2 to 5 and was used by Jaguar in the XJR and XKR supercharged V8's. They pop up on eBay from time to time. PCS has a TCU that someone in the USA has used to control it, check out the PCS website they are listed in the dealers.

Other than that and what I am planning is a 4L60e and gear vendors will give you a 7speed auto. This I think is a more cost effective solution.

 

how does the gearvendors gear selection work?

 

A Ford 5R55 S looks like a good candidate. Availability, aftermarket support, pricing, gear ratios, size and torque capacity are all in reasonable ranges.

 

what about the bellhouse?

 

Adapter plate is the current theory. Have not done the actual measurements.

 

i think that a Ford 5R55 trans would be border line for strenth, might work but at its end of
its design level, it mates to 225 hp engines unless you could find one out of a supercharged XF, or some late model ford V8 cars RWD.

if i was going to such an area of mods might as well go to a newer 6spd auto.

i dont even want to think about new 7and 8 spds showing up!

 

got it, Ford 6R80 auto trans,, 6 speed, lockup convertor, 500ft lbs torque capable. probably take more than that.

OK fits lot of exlplorers, F-150 trucks, big RWD sedans , grand marques, gotta be many of them in junkyards, 2002 to present.

what im sayin is if you are gonna do the mods,adapting, electronic controls,etc. go for a 6spd.
a strong one you wont worry about breaking.

 

also check out a GM 6L80-E, gonna be harder to find tho 2006 up chevy trucks , cadillac RWD, corvettes, .

be a nice conversion , but maybe simpler to go 4L60-E, with a gear vendors!

 

I haven't figured out what one would do with 7 or 8 speeds. I'll look into the 6R80 size and gear ratios too.

 

Forget the later ZF or GM 6L80 6 speeds there are currently no after market TCU's to run them I have already done the research.

A 4L80 or 4L60 will do 7 speeds with a gearvendors with very close ratios between 1 and 6. I also had a quick look on eBay and the Merc AMG box is under a grand and these things go behind the 1000Nm SLR Maclaren very strong box. Which ever way you go you will need an adaptor.

 

FYI, a 4L80 is 40lbs more than a 4L60, much higher torque rating.

but its also larger,physical size, so have modify the trans tunnel.

how do i know ,already done a camaro , convert from 4L60 to HD 4L80, different driveshaft also,bigger, course you (almost) cant break one!

ques: do the Merc, use the 60 or the 80, im thinking an 80, to handle 1000NM torque.

seems that ZF and GM collaborated on the 6pd auto.

AH YES! i love car history, GM hydramatic, developed the first real hydraulic trans, introduced a 4spd in the 1939 Oldsmobile.
and patented many of its design engineering, must have been good , latest studies show that Mercedes and ZF pay royalties for licensing rights.

also some Toyota trans, uses some of GMs basic designs.

but a philasophical problem, is GMs Allison gear division,late 30s, designed the auto trans, for a completly different reason , for KILLING People, HAHA , what would one use a War tank for?,(just one reason)!

OH well, lets move on.

 

Mercedes manufacture their own transmission the 5 speed is a 722.6 and there are at least 4 different versions probably more. All have the same ratios but the AMG versions (and Jaguar XK/JR) have more clutches and beefier internals. These are brilliant transmissions and accelerate just like a manual. I had an AMG a few years ago and was most impressed with the trans.

cheers
Warren

On a side note Porsche used the Merc 722.4 (4speed auto) in the 928 it was modified to mount in the rear of the car.

 

warrjon, of course Merc manufacture there own trans, (but they could have an outside vender also)!!

as GM manufactiures its own trans. 2-3- 4-5-6-7-8-speeds hydraulic trans.

and modifing a trans for hi-output, has been a standard procedure in USA since the early 50s, old fashioned HOTRODDERS, did all types of machining,welding,etc. and oil pressure mods.
tons of stuff out there, wouldnt take long to mod an TCU,for a 6spd.

m90,, FYI in usa , most trans models use like a 4L60, the first # 4 means how many speeds it is,, the second # L means RWD, a T means front WD, and the last # means torque rating.
so a 4L80 is a four spd, RWD, torque rate around 500ft.lbs.(those tor, # can vary tho)

ford also has adopted simular designations.

Corvette also has a rear mount 6spd , of the 6/80 specs.

and in USA we have,4L65 and now 4L70s to play with, all in the 4L60/ 700R4 demensions,
the differences being,they have more planetary pinions, plus other HD mods , they are tough units.

and Warrjon im not taking anything away from German stuff, i know its good,
just like all modern auto trans use some of the BASIC engineering from the old GM units.

NOW when we get into the NEW Dual clutch transmissions, its a completly differnt story, that stuff is moving quickly in it engineering.

now do you know that the 1st DCT , and the patent rights are owned by BORG=WARNER of USA ,Detroit Mich.

last but not least,aftermarket race parts for these trans. are easily available in USA.

i suppose you can tell im AMERICAN, haha.

 

I'm thinking a 4L65E with John's Cars kit may be the best solution. Would handle a modified V12 and still be one of the cheaper and easier solutions.

 

No Merc only use their own transmissions. BMW on the other hand use ZF and GM, I know they used the 5L40 in some of the 3 series.

Yeah the 4L80 is a good transmission very strong and probably in abundance in the US. They are like dinasore droppings here in Aus $1000+ for a second hand. I have a 4L60e to go in the XJS, stock to start with but I will have to upgrade it before the engine rebuild to increase its strenght considerably. They have a bad rep here for dropping their guts with high HP, but they are plentiful and cheap.

 

good choices,, 4L60 or 4L65, the 65 has a 5 pinion planetary, versus 4 pinion for the 60, but dont sell the 60 short, its is improved over the old 700R4,metalurgy ,hardness ans such.

plus both are lighter in weight,and shorter in length.

idid my conversion back in 1995, 78 xjs, from GM 400, to 700R4 modded with a shift kit, no electronics(would have used a 60E but werent made YET!). the TV cable works fine with the spindle cable mount(takes a little time to adjust shift points).

made my own adaptor kit, adaptor plate for adapting a Chevy trans to BOP(buick oldsmobile,pontiac), made a pilot bushing that spaced the convertor the correct amount(dont want it out to far OR jammed in to far). redrilled the Jag flex plate carfully!

and i use a 10" convertor ,advantage is quick revs, like a lightweight flywheel, but has
400 guts in it.

made rear trans mount from piece of channel iron,used a standard chevy rubber mount.

had drive shop make custom Aluminum driveshaft, with HD joints,single piece.

changed rear ratio to 3.73, end up with nice lower gears for acceleration and final is a hyway cruiser of 2.60.

works for me 15yrs!

i suppose a final ratio of 2.25 would be doable with a 6spd, but im not gonna change things now, and it would take some floor body mods to get a Gearvendors in there ,plus another drivshaft etc.

keeping in mind that the XJS platform uses the tunnel as a reinforcement, to make sure you dont end up with a rubber car.haha

 

6x Six-Speed GM 4L80E Automatic Transmission (850hp) - TCIŽ Auto


This is getting alot of press in the aftermarket. It would require the same adapter as any other 700R4/4L60/4L80 swap, but offers full computer control of the transmission thru a separate controller. Paddle shifter would be an option.

 

is the V12 a BOP bellhouse? ive got a BOP T400 in the shed