Drivetrain Tko 600 Install Help. Tunnel Clearance Issues

Hey all, I've searched and searched for days and I can't seem to figure out my problem so perhaps you folks can help me.

I am attempting to install a tko 600 behind my new 347 in my 88 fox and I cannot for the life of me get it to clear the trans tunnel. I can get it to "work" but cutting the tunnel and making it fit but the tko install seems to be a common practice and I have never heard of anyone having to do that to make it fit.

Here's the info.

88 Fox
347 stroker
tko 600
tremec bellhousing for the tko
tubular crossmember. Stock has already been cut off
solid motor mounts, poly trans mount
stock k member (notched out a bit to get the oil pan to clear)

Transmission connects to the engine just fine with the new bellhousing, everything lines up, but when I go to put it in the car I can't get it in all the way. It's hitting the first dimple in front of the hole where the shifter goes. The oil pan hits the k member because I can't get the transmission up any higher to clear it. Trying to jack it up any higher results in the whole car being lifted up.

It needs to go up another 1/2" or so in order to install the plates that were sent with the tko install kit. If I can install those then it will get the oil pan off of the k member.

The motor mounts have already dropped the engine as far as it will go so I'm at a loss at this point.

I'm trying to figure out what the issue could be. Can a stock k member not be used? Did I install the crossmember wrong? I can't drop it any lower than that. Try different motor mounts that don't drop it as low?


TKO 600
https://www.astroperformance.com/product/tremec-tko-600-5-speed/
Tremec bellhousing
https://www.astroperformance.com/product/new-tremec-tr-3550tkotko-500tko-600-5-speed-bellhousing/
Stifflers Crossmember
https://lmr.com/item/STF-TCBM01/Transmission-Crossmember-Tubular-79-93-Aod-T5-And-Tko
Stifflers install kit
https://lmr.com/item/STF-TKOM09/Mustang-Stifflers-TKO-Install-Kit-TCB-TKO




Thanks in advance

jrichker said:

I have a Tremec 3550 which has the same external shape and dimensions as a TKO 500/600. I have had the transmission in and out of 2 different 89 Mustangs multiple times. I never had a problem with the transmission clearance with a stock k member and rear crossmember on the first Mustang.

I looked at the crossmember and you have it set up with the spacers incorrectly installed. The spacers should allow the crossmember to sit all the way to the rear. The rear rubber bushing should sit against the metal of the body mount.

Mine needed a little extra clearance so I had cut the ear off the rear rubber bushing and put it on the front. I had to do this for both driver and passenger side mounts. If I didn't, the crossmember rubbed against the tailshaft housing.

The picture below is of the passenger side crossmember mount. The left side of the picture is towards the rear of the car.



The picture below

Click to expand...

Thanks for the reply,

This is how I have it installed now based on what the instructions said. Are you saying I need to have the crossmember sitting all the way to the rear instead?

I tried moving the spacers around but the problem with the top of the trans hitting the trans tunnel remains the same. The transmission is pinching against the trans tunnel not allowing it to move at all. I need the transmission to move up about 1/2" in order to get the spacers between the bottom of the mount and the crossmember in order to get the driveline in the correct spot. It's pushed over towards the drivers side a bit meaning in order to get it back towards the passengers side I'd have to cut more of the k member. But you saying you've never had issues with the stock k member clearance leads me to believe I might be doing something wrong here.

jrichker said:

e
Exactly.

That 's part of the T5 to Tremec 3550/TKO conversion process with the OEM crossmember.

If I were in your place, I would loosen the rear transmission mount bolts and remove all the spacers and see where everything lines up without the spacers in place. Then add spacers back in to maintain that spacing.

Click to expand...

Thats what I did then took the picture in post #4. It's off horizontally as well as vertically almost as if the whole thing is misaligned. Only way I see to get the trans to line up with the crossmember threads is to cut more of the k member and shift the whole thing over a half inch or so. Which I haven't heard of anyone having to do before.

It almost seems like the entire frame is twisted or something.

jrichker said:

It is time to have it towed and the car put on a frame machine. The answer ma not be what you want to hear...

Click to expand...

I was really hoping that wasn't the case and that I was maybe doing something wrong with the installation...

The last ditch effort I'll try is to install poly motor mounts tomorrow which will raise the engine up about 1/2" over the solid mounts and see if that will help. If not then I suppose I'm off to frame shop. But yes you are correct that isn't the answer I wanted to hear of course...I've been searching around high and low for a week hoping it was anything but that.

If that ends up being the case then I will have been screwed out of the $5000 I spent for a car with a bent frame....