shern

iTrader: (6)

I seem to have hit a snag on my R154 swap. It pertains to the transmission mount and the crossmember.

Most threads I've read insist that you can reuse the W58 crossmember and rear mount with the R154. However, I have found out that there are two different types of R154s out there and I happen to have one that does not allow reuse of the W58 crossmember and mount. Nothing lines up. In addition, the MK3 mount has a center screw that isolates the rubber mount that does not allow bolting to the W58 crossmember.

Here is the R154 box that allows you to use the W58 crossmember/mount. As you can see, there are two mounting holes offset from the other two, the same as the W58


Here is my R154. It has all four holes aligned in parallel.



2JZLEX used this crossmember on his R154 swap that will work with the MK3 mount. What car is this crossmember from? All of the W58s have the solid aluminum crossmember.

Blizzy

iTrader: (-1)

I have shared PMs with 2JZLEX about this very part. He has told me that he is unaware of the year, but that this crossmember came from a W58 MK3 Supra.

With your R154 bolt pattern, it is my understanding that you will only be able to bolt the MK3 transmission mount to your transmission. Even the early version W58 mount for the SC has a different bolt pattern.

Another option -unverified but suggested to me by Neil Griffiths in Australia- would be to drill and tap the third hole on your transmission and acquire the early version Soarer R154 transmission mount.

shern

iTrader: (6)

Thanks for the insight Mark.

I don't believe it's from a MK3 Supra. I have the MK3 Supra crossmember that came with my R154 and it is much shorter than the SC300. Unless the width of the transmission tunnel was shortened at some particular year.

I think I may have actually found a solution. It looks like 2/4 R154 mounting holes line up with the W58 mount if you extend the holes back approximately 3/8" on the W58 mount. It will allow me to reuse the aluminum crossmember and W58 mount but I need to check the height. Unfortunately, it will only allow using 2 screws but it should suffice. I just drilled them out and should be able to report out later today.

Unfortunately, my daughter busted the dig camera so I'll need to find another one.

YeA 2jZ

iTrader: (15)

damn this is good info shern i have recently decided that i too should go with an R154 with my build so these kinda threads are very helpful

TLDriver

iTrader: (4)

I used the w58 crossmemeber and only used to bolts for the transmission. I have seen others use the MK3 and they redrilled it to fit the car.

shern

iTrader: (6)

Problem Solved

After putting the W58 crossmember and mount up against the R154 and aligning the holes on the chassis, I noticed there was just enough room to enlarge the bolt holes on the W58 mount to get 2 screws in on the R154. After lengthening the holes, everything lined up perfectly.

Here are the W58 screw holes lengthened to align with the R154 holes.



You can see the screws in the new holes in the W58



You can see the W58 crossmember with everything aligned.

YeA 2jZ

iTrader: (15)

nice work man what did you use to make the lengthen holes is it a secure fit?

shern

iTrader: (6)

Drill + dremel (cutoff disk and grinder).

Blizzy

iTrader: (-1)

Just a thought...

You could get some heavy duty cable ties (I have seen some 150+ lb ones at the hardware store near me before), run them through the back holes on the transmission mount, up and over the tail housing, and pull them tight. Those bigger cable ties (at least the ones I have seen) are reusable with a little slot to alleviate tension using a screwdriver, so you would still have a modular set up while adding additional stability through the transmission mount.

I say this since the transmission mount is just such a vital piece to minimizing the vibrations in the driveline. I suspect that adding the cable ties would only minimize your vibrations, or at least just add some insurance in that department. Again, just a thought...

shern

iTrader: (6)

I'm gonna give the two screws a shot. If I find that they are not enough to quell any issues that may occur, I'm gonna have a custom crossmember made by a local CNC shop. I'll let you know how it goes.

YeA 2jZ

iTrader: (15)

keep us informed i will bump this if you dont =)

Ali SC3

iTrader: (10)

Im not sure that is very safe. you may have some flex front to back with slotted holes.
I would use some quality bolts, because it looks like if the engine/trans were to rock forward, when it rocks back that bolt is going to slam into the edge of the slot and it could possibly break the head off.

I wonder if you could just tack weld the back part on instead of using the rear 2 bolts. Sure the mount will be one with the tranny, but you could always get another one later or cut the weld off down the road.

shern

iTrader: (6)

I agree with you to a point. The Lexus transmission mounts are like marshmallows, even when they are brand new. There is no way that the bolt will slide before the marshmallows give first. I suspect with a poly mount, your scenario could happen.

However, it might be a good idea to use lock or serrated washers just to ensure I get a tight lock on the bolt.

Ali SC3

iTrader: (10)

thats a good idea, you could always slot it more so it cant hit either side, then lock it in the middle. Im sure youll figure something out. i've never messed with one before.

1JZPWRD

iTrader: (59)

Bumping old thread. This is the same issue that I have currently with my R154. I think I will have local welder fill in one side of the holes completely on the crossmember. Then once aligned I will just redrill new holes to match the rubber mount on the tranny. Makes better since and you can use all four screws on your mount and crossmember.

My question is do I remove the center bolt on the oem r154 rubber mount or leave in place?


What's is purpose to adjust the height of the tranny somehow?


That's the thing I know to do. Someone chime in and let us know what you did!!!