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ok thats what i would have thought, the sensor the speedo uses will be at the output of the gearbox. Lexus and probably most other makes these days usually have more than one speed sensor on the car for ECU/ABS/TRC etc so its just a matter of which one the speedo runs off
ok thats what i would have thought, the sensor the speedo uses will be at the output of the gearbox. Lexus and probably most other makes these days usually have more than one speed sensor on the car for ECU/ABS/TRC etc so its just a matter of which one the speedo runs off
No, it's not at the output of the gearbox. The Skid control ECU produces the pulses for the speedometer/odometer. It gets input from the wheel speed sensors, but it only uses the rear wheel sensors for speed.
Either the speedo uses a sensor on the transmission, in which case it will be affected by the diff ratio, or it uses a sensor on the wheel hub(s), in which case it wont be affected by the diff ratio.
Whether the front or rear hubs are used doesnt make any difference, it still wont be affected by the diff
I think what Lobux is explaining is that the skid control ECU inputs a signal from the rear wheel speed sensors for its own collective data and then outputs (shares) the signal with the speedo in a language that the speedo understands.
Can't wait for the outcome, did a m3 diff swap on my previous 328 and it was day and night, this could be one of the cheapest go fast mod for isf if it works
If im lucky i *might* get a chance to get this fitted before the new year but no guarantees as work + moving house means not much time
in the meantime I might grab one of the Soarer/SC400 diffs ive got lying around and compare to see if this gearset is compatible or not just out of interest
This is an open diff centre out of a Soarer/SC400 with the new crown wheel sitting on top
Same dimensions everywhere except the Soarer one is noticeably thicker. At first i thought that meant these two diffs are not compatible, but thinking about it, Toyota does not use shims to position the diff centre left/right in the case. I think they just manufacture the crown wheels with a particular width/offset to match up with the size of the pinion, and then adjust teh pinion crush tube to get the correct meshing of the gears.
The Soarer diff is a 3.92 which means a 12 tooth pinion. This means it is physically smaller than the 15 tooth pinion of the 3.27 gearset i have here, therefore the Soarer crown wheel needs to be thicker to line up.
So its likely that the new gearset would bolt straight into this diff. But i dont want to do that because the diff case isnt as good (doesnt have the extra size/cooling fins of the IS-F one) and also the stub axles will be different so i would need to swap them
They definitely use shims for left right fit in the IS-F case. The snap rings are varying thicknesses. PNC 41334D. There are also washers for the pinion gear.
I havnt forgotten about this, but the holidays were a pretty stressful time in which i moved house and had a bunch of other issues to deal with. The car didnt get a look in.
i had a couple of days free to work on it this week, but that time was taken up installing a set of PPE headers....
I have decided to arrange to borrow another car because its proving just too difficult to take the IS F off the road for the time it will take to do this mod while it is my only running vehicle...
Hopefully that means i may have some news fairly soon
[edit] and now ive signed up for a 1000m runway drag event in April, so that will be the first real test of this diff!
Sci- what's going on with the gearing swap? I either want to find something to fit the f housing and sell my 350 giken setup or a lower set for the 350 carrier!
In February my car was hit by a drunk driver and spent two months getting repaired at a cost of thousands.
Then i was busy moving house. Its only recently that ive been able to think about getting this done, and im making some tentative arrangements for the end of this month.
Rest assured i will update this thread when something happens
Should measure the ring gear thickness for me I have my f diff out and apart still, I can't verify the 350 ring thickness due to it still being in the car but I know the f ring is thicker than the 350. The problem I encountered was the 350 LSD to ring gear mating flange was offset more to one side than the F's. I tried putting the f ring on the 350 LSD, into the f diff carrier and it will not work.
I am not really excited about how this has dragged out. I was hoping I would not have to be the guinea pig for this, but given I will be installing the Giken spool fairly soon, it might be the best opportunity to find out. I just wish I could find the parts for cheap instead of having to buy a very low volume piece, then have a hard time selling it if it does not work.
Lobux did you get the F giken? If so then you are fine, just swap them around. I was talking about the 350 giken unit, it doesn't have the same ring thickness as the F and that causes the ring mounting flange to be manufactured more offset than the F's. If you got the F unit and decide to go without it hit me up, I'm wanting to put my stock gearing in but I'm waiting to get the F unit to only swap the diff 1 more time due to the somewhat hassle of removing it. Overall it's not too hard of a task just use a pry bar and a heavy hammer to remove the axles, alternating 180 degrees apart on the machined side of the cv housing don't pry between the diff and cv housing. I also did the swap by only removing the subframe braces and mid pipe back on exhaust.