Hi,
Anyone know what\'s involved in changing from a 4.1 ratio diff to the autos 3.9. Do you need to change the whole case and drive shaft or just the internals? If so does it then need to be shimmed etc?
Ive always wondered how much of a job this is, are you going for a top speed monster? or just better mpg on the motorway :)
Quote from: ScuttleRXIve always wondered how much of a job this is, are you going for a top speed monster? or just better mpg on the motorway :)
mmmmm no just doing a bit of research for a possible conversion that would mean I\'d have an engine that wouldn\'t be happy reving over 6k
Ah I see, keep toying with the idea of going the other way 4.1 ----> 4.3, but think there are more cost effective and essential things for mine before that.
What engine are you thinking of going for? or is it hush hush for now
Quote from: ScuttleRXWhat engine are you thinking of going for? or is it hush hush for now
If I go for it, LS1 or LS2 V8 but it\'s a while off yet if at all.
just the final drive ring gear, take the diff case off the car then unbolt the casing then u can see the diff inside with the ring gear bolted to it, there are two bearings you have to prize off first and some shims, took my mechnic an hour and half to do with the proper tools to change the diff, in this case you will be just swapping out the ring gear
is it me or are more and more people in the uk contemplating the LSX swap, go for it, the hinson supercars subframe for RHD is going to be availiable soon (so i hear) will make things very easy.
Been on swapcartech?
Yep, you rhdv8
Yup it may seem that theres alot of interest or it could be just me getting about alot lol
I know what you mean, its a case of look but dont touch for me at the min. cant wait to see one in person. I think the LS2 is the way to go over the LS1 bit of extra work but cant beat cubes if FI is not a viable option, some people have even got ls7\'s running in there FD\'d
As my goal isn\'t all out power, if I go for it I\'d go LS1 first, see how it goes then if needed you can always add cubes.
the easiest way to swap to 3.9 from 4.1 is to just fit the whole auto diff (3,9) all you have to do is swap the drive flange on the front for the manual one . i use a 3.9 in my ls powered fd and its better than the 4.1 but with the 6 speed the gearing is good anyway 70mph=1700rpm which is very relaxed. a ls1 with a cam and set up properly is good for 400+bhp about the same as ls2 and for a lot less money ,the ls2 also comes with fly by wire throttle etc. if you are going to buy a ls just make sure its a 2001 on as they are better . just ordered my 7.0 litre short motor rool on next year !!!
Sorry for Hijack but any chance of seeing pics of your car Tinker (or in person if only in Birmingham)
I am really considering this option when / if my engine blows.
Cheers
Eddie
Quote from: Crazy EddieSorry for Hijack but any chance of seeing pics of your car Tinker (or in person if only in Birmingham)
I am really considering this option when / if my engine blows.
Cheers
Eddie
If he takes you out - put your seatbelt on! He likes going sideways, even in a straight line. Obviously very much in control though :cool
(//image003),(//image004),(//image005),hope these work they are lod pics of the 5.7 motor its now 6.3 (soon to be 7.0) my car is not here at moment as i am doing one for my freind but you are welcome to have a look at that if you want cheers craig sorry the pics dont seem to work i can email but i cant post for some reason ? email me and i will return pics tinker-27taylor@blueyonder.co.uk
Your cheapest option is to change the complete diff in one go,casing and all! I blew my diff and managed to swaff the crown wheel n pinion as well.My original ratio was 4:3 because it was the RZ diff,i didn\'t want to have to go down to a second hand 4:1 out of a standard rex diff or pay the mazda price of £700 plus vat for new 4:3 crown and pinion.I was offered a 4:4 out of a rx8 diff so i bought that. I had them fitted along with the new Kaaz diff by a top rally mechanic/engineer.The process wasn\'t easy or cheap! He had to press the pinion out of the rx8 diff then refit into the rx7 diff and seat it correctly at the right depth/level,new shims had to be milled to fit exactly and the backlash set. As stated in a mazda workshop manual you need a special measuring tool to gauge the seating depth of the pinion. Thats why i left it to the professionals. Cost me but i\'m safe i the knoeledge its been done right.:)
yeah just swapping the complete diff to an auto one is the cheapest option.
When fitting my Kazz diff it cost me approx £500 for the Kazz diff and £100 labour to have the diff/casing dropped out of my car , the old diff taken out of the casing, the final gear ,shims,bearing taken off and put onto the new KAzz, then refitted and put back on the car.
So I paid £600 total
Quote from: tinker-27the easiest way to swap to 3.9 from 4.1 is to just fit the whole auto diff (3,9) all you have to do is swap the drive flange on the front for the manual one . i use a 3.9 in my ls powered fd and its better than the 4.1 but with the 6 speed the gearing is good anyway 70mph=1700rpm which is very relaxed. a ls1 with a cam and set up properly is good for 400+bhp about the same as ls2 and for a lot less money ,the ls2 also comes with fly by wire throttle etc. if you are going to buy a ls just make sure its a 2001 on as they are better . just ordered my 7.0 litre short motor rool on next year !!!
I am also looking at the diff option, as it\'s now all too lower geared, but Pip recons the 3.9 may not be enough. Need something else? Ideas...
Norm, we have a 3.9 from an auto in ours and it makes things a little calmer on acceleration.
Am I right in saying, it curbs off the line ripping strain a little, whilest giving better top end? I need it not to sound like it\'s reving it\'s head off at 70 or 80MPH, first gear is almost usless now!
thats about right