1. Drivetrain
2. How to get your 520/555/523/568 transmission to work with the SRT4 engine

This article was written by rbryant on 01-02-2009.

As is tradition with Chryco not much changed when the switch from the 2.2/2.5 platform to the 2.0/2.4 platform was made.
The only real change to the bellhousing pattern was that the starter is now on the front side of the engine for the 2.0/2.4. In order to accomplish this they moved the lower front transmission attachment point downward to give room for the new starter location. Luckily they didn't even move the rear location and left everything else where it was!

Many people have created engine mounts that clamp the new style block to the old style transmission.


Bellhousing Modificatoin Method

Another way to do this is to simply weld in a new tab into the bell housing using a piece of 1" round stock that is then drilled and tapped:




I believe that this is a better solution considering that the mount would have to be fabricated and it would still be a less optimal solution. This way a stratus/caravan front mount can be used and only the front connection of the mount needs to be fabricated.

I did not include the dowel recess in the mount. I did not do this because no matter how accurate you get the placement it is still the least accurate mount on the transmission. I knocked the dowel out of this hole on the block and relied on the back dowel position to help center the bellhousing. Because the dowel is removed special care and checking should be done to be sure that the bolt holes are centered to the block.

Aligned back top:


Aligned Front top:


One option that I considered afterward was to add the dowel to the top front boss on the block and drill the sleve on the top front bellhousing location. This would be more accurate than adding it to a new boss because you can simply enlarge already centered holes. This is debated in a thread here:

http://www.turbo-mopar.com/forums/sh...ad.php?t=15931



Starter Mounting

Once this issue is solved the starter may or may not work without modifications depending on the year of your engine block.

2000 and older 2.4l block:


2001-2002 2.4l block


2003+ 2.4l Block (SRT4 is the same except it has the oil return line drilled):


The first 2 blocks will allow the starter to fit without modifications.

The final block requires that the Nippondenso starter be used and modified in order to make it fit without grinding into the oil return passage for clearance. I am starting to like this starter actually because it doesn't have a plastic solenoid housing that can melt under the turbo. The motor is actually on the side of the starter and the solenoid is located inside of the main body. I will have to wait and see if the starter motor its self melts or not....

I have also seen pictures where Bosch gear reduction starter was used but it required grinding on the block's oil return line. The Bosch case can't be ground down like the Nippondenso starter case can because it is a flush steel case that surrounds the starter motor.
This is how I modified my Nippondenso starter:


The grinding of the case is safe. The casting just extends the bolt holes from each side for simplicity.

I did actually make a new double strap and also drilled out the hole on the left side to take a bolt with a nut rather than threading it through. (will update pictures later). the electrical wire is touching the block so be sure to add an extra layer of insulation. I am going to use a fabric heat shield.
I also found the oil drainback to be very tight so I tapped the hole with a 1/2" NPT and plan to run a 45 degree AN-10 fitting to connect the oil return line from the turbo. Make sure to run the tap deeper than normal so you can get the fitting as far into the block as possible. The clearance here is still very tight even with the 45 degree fitting. I then run a 45 degree fitting on the oil drain line in the opposite direction to get the oil flow path to be as good as possible given the limited clerance.

I still think this is a better option than welding a fitting into the oil pan because it keeps everything away from the axle!
This is a tough place to tap because the tap handle doesn't fit. (use two wrenches instead or pay the machinist to do it):


Note that the custom dust shield has both the 2.2/2.5 and 2.0/2.4 front mounting holes on the lower left side of the picture. The 2.2/2.5 is the higher of the lower mounting holes.

BTW: I recommend not using the small bolt that connects the dust shield to the block. It makes alignment a nightmare and it can't be removed with the flywheel installed!



More Pictures of the engine/tranny combination connected coming soon...

-Rich