Eric250

My transmission just went out. Kind of want ro swap to a manual any suggestions on what to do? Please n thanks

Jeff Lange

iTrader: (1)

This swap is definitely possible, however I can't recall anyone doing it on an IS250 off the top of my head. I'm going to give you a rundown of what is different and what you would need to get and what would be nice to have and what you can get away without.

Manual transmission with shifter assembly, release fork, release cylinder and bolts to engine (some are different lengths)
Rear transmission mount and bolts to transmission
Flywheel, clutch, pressure plate and release bearing
Driveshaft (at least front section, but better to get entire assembly)
Differential (different gearing, however the auto differential is actually a bit nicer, I wouldn't change it)
Engine mounts (IS250 MT uses the same mounts as the IS350; they are stiffer, you can get away without them)
Engine drive belt tensioner (IS250 MT uses a stiffer belt tensioner to avoid the belt losing tension under hard shifts; can likely get away without it)
Clutch pedal with bracket assembly
Brake pedal
The dash reinforcement that runs across the car is different, some modifications can likely be made to fit the components required
Brake master cylinder reservoir
Clutch master cylinder, lines, hoses and hardware
Centre console box and covers
Gauge cluster (not needed if you don't care about the PRND... lights on the dash)
Parking brake handle, boot and front parking brake cable
Shift boots (rubber and leather)
Firewall needs to be modified (there is no hole for the clutch master equipment on auto cars)
The carpet and sound deadening under it are different in the centre console area
Manual transmission engine computer
Manual transmission power control computer (can use the automatic computer - will determine whether the brake pedal or clutch pedal is pushed to start the engine, this will depend on if you replace the dash harness/engine harness or modify them to work and if you modify them how extensively you do it)
Engine wiring harness (can modify the automatic harness to work)
Dash wiring harness (can modify the automatic harness to work)
Clutch pedal switches for starting and cruise control (not required if not modifying the car to start with the clutch switch, cruise control may require additional modifications, but can be made to work)
Parking brake and back up light switch harness connector (if not using actual manual transmission harnesses)
Clutch pedal switch connectors (depending on what modifications are being done)

Once all of the parts are installed and the wiring modifications (if needed) are completed, you will need to handshake the engine computer with the rest of the immobilizer system in order to start the car, and then reinitialize the ABS/VSC computer using a Techstream in order for it to pull the manual transmission parameters from the engine computer.

I think that is more or less a complete list of what you'll need. There may be a few bits and pieces here and there you may also need, but not many. The wiring modifications can be relatively light if you aren't concerned about cruise control or that the car starts with the brake pedal instead of the clutch pedal. Doing it correctly isn't too much harder to be honest, but there are a few things to do on the dash harness for sure. When I did the engine swap in my car, luckily most of the modifications I had to do electronically were on the engine harness and engine bay harness, as there was no IS350 6MT engine harness to start with, haha.

Hope that helps!

Jeff

Gville350

iTrader: (10)

Jeff must have been bored this morning!

Bichon

Glad he was; fascinating reading!

Jeff Lange

iTrader: (1)

Nobody talks about what actually needs to be done, just the regular old "sell the car and buy the one you want." The 2IS is getting older, simply selling your car and finding one just like it but with the different thing is going to get harder and harder to do, especially as they get more used and abused.

The biggest concern even versus the 1IS is that finding used MT parts can be harder to do, but I figured the information should still exist, haha.

One day maybe I'll post the actual specifics of what would need to be done electronically... but only if someone is actually going to do it, otherwise it's just a waste of time.

Jeff

timmy0tool

iTrader: (7)

good post, and I'm sure will deter the OP haha. it's not for the faint of heart (and shallow pockets).

any idea on the cost jeff?

Eric250

Thanks alot jeff that was deff useful knowledge. Let me start pricing some things out let yall know tge final decision

2013FSport

iTrader: (2)

I can see the rev limiter being challenged if the clutch pedal switches are bypassed and you enable Cruise AND shift or inadvertently depress the clutch! Ziiiing to 7k!!!

Jeff Lange

iTrader: (1)

It won't rev past rev limit, but yeah, it's not great. Definitely want to get the clutch switches in place if you can, and even more so if you want to use cruise control.

Jeff

t3hHott

hey Jeff you still around?

anyone else do an auto to manual conversion yet?

AFlex

@Jeff Lange Sorry to jump on an old thread but I couldn't find anything in the search results. Thanks for the above list of differences between MT and AT parts - I'm looking to get hold of a replacement driveshaft for my IS250 MT and there are hardly any MT salvage cars over here in the UK.

I take it I can't just lift a driveshaft from an IS250 AT then? Are there any other models that use the same driveshaft? e.g. the IS220D or IS200D?

Also, what would you say is nicer about the AT differential? Is the gearing higher or lower? I find that the gearing is a little too high on my IS250 MT to the point that 1st gear is pretty much pointless and 6th is not efficient enough.

Thanks!
AF

Jeff Lange

iTrader: (1)

You can likely get away with using the rear half from an IS250 AT RWD or a 2009+ IS250 AWD, but the front half is IS250 6MT specific.

As for gearing, I suppose that is personal preference, but I am very surprised to hear your comments, given that the European cars used taller gearing than anywhere else.

3.58:1 - IS250 6MT Europe-Spec
3.73:1 - IS250 6MT North America-Spec, 6AT RWD Europe-Spec
3.91:1 - IS250 6AT RWD Except Europe-Spec
4.10:1 - IS250 AWD

Jeff

AFlex

Thanks Jeff. Is there a way to separate the two halves then? I had read elsewhere that it isn't a serviceable part and the U joints are not replaceable- you have to buy an entire new driveshaft...

EDIT: Just had a quick read up on final drive ratios and I can see your point - 1st gear must love to rev high in the US and Canada then! I think I can get to about 20-25mph at redline. This must also be why the 0-60 times quoted in the US seem to be faster.

And as for 6th gear, I'm at about 70mph at 3000rpm which in my opinion is still too highly geared at least compared to other German cars I've driven.

Anyway, thanks Jeff - as usual you are a treasure trove of information!

RotaryForc

Hi @Jeff Lange sorry for bumping this old thread but I am really looking forward to do this manual swap (I even went to a junkyard to buy everything needed but I regret as gearbox condition was awful). Someone told me that I would have troubles with ABS/VSC ecu and so on. You told that you may post what needed to be done electronically, did you post it? Ive searched your posts and didnt find anything. I would be really pleased if you could do it.

Thank you!

2013FSport

iTrader: (2)

I suggest you make an account on Toyota's TIS site and pull up an auto and manual trans vehicles and compare the two schematics as you will need it in the end.

While you're tinkering, consider dropping in a 3 liter 3GR power plant. Many before you have and 2.5 ECU is happy to comply.

To the previous poster w driveline issues, they have driveline service shops that can resolve these issues pretty easily.