And yet another 300d Manual Transmission Thread

[wtsane]

I have been threads on this forum, and other forum threads, and am not far from purchasing a 4-speed from a 240D, to install into my 1985 300D. I think (think) I have a handle on most of this, and have previously converted my 1974 Volvo 144 from the three speed automatic to the M-41 4 speed with overdrive, so I have some frame of reference. Having said that, this looks to be an increase in the level of complexity over my earlier effort. From these threads I gather (please correct me where necessary):

1.) It is possible to put a 240D manual transmission into a 300D

2.) The bolt patern on the bellhousing and the engine are compatible.

3.) Modification is necessary to the shifter linkage, crossmember, driveshaft, and pilot bushing are necessary

Questions:

1.) Are there specific measurements available for the modifications?
a.) angle and length of the shift linkages
b.) length, OD and ID of needed pilot bushing
c.) best crossmember to use (240D/300D)

2.) Does anyone have a source for a ready to use pilot bushing (part number perhaps)?

3.) Key lessons learned from the install?

4.) Performance result specifics over time, drawbacks in daily use?

Thank you in advance for any advice or input

WTSane

[charmalu]

Yes a 240D 4-spd manual trans will bolt up to the 85 300D. However, as I remember, the hole in the end of the 85 crankshaft is a different size, and won`t take the standard pilot bearing.

The 240D manual Flywheel will bolt right in.

The transmission will bolt to the 617.952 adaptor plate and engine

You can use the 85 adaptor plate, and still use the tach pick up sensor that gets it`s impulses from the FW.

Use the 240D transmission X mount from a 240D automatic.

The shifter will bolt right in where the auto shifter was. uses the same holes.

The shift rods will have to be shortened some, threaded and tweeked a little to fit.

You will not need the NSS harness, but will need to pull it into the cabin through the gromett to the right of the fuel adjustment device. (Gas peddle ) 2 wires are for the back up lights and the other 2 are for starting. the purple one`s as I remember connect to the plug just above the carpet tunnel on the same side. the other 2 to the back up switch from the shifter.

Use the front driveline section off a 240D, and have it shortened and balanced. may be a good time to replace the center support bearing and check the U-joint.

The 85 has the 2:88 differential and is good on the highway for cruising. I changed my 85 a couple yrs back, seems like a gear between 3rd and 4th and one between 2nd and 3rd would be good. you will be using 3rd around town and on the freeway during heavy slow traffic. when you get below 2700 rpms I drop her down from 4th, can feel some vibs. anything above 3000 and she is a good runner on the highway.

When you pull the auto trans and swap in the 4-spd, the front end will be riding high. the 4-spd only weight 54lbs. not sure on the auto, but they are heavy.
I installed a set of 240D front springs, and it brought down the front to a good ride highth. only down side is on a windy mountain road, it is a little soft in the turns. normal driving, it is great.
I have a 300TD front sway bar to install, they are 2mm thicker. and need to get it in before this winter.

would I do it again? you bet.

you may ask how I got around the pilot bearing issue it being a 85. the engine is a rebuilt one from a different year, and or a different crank.

http://www.peachparts.com/shopforum/showthread.php?t=294398

http://www.peachparts.com/shopforum/showthread.php?t=302284

this post is from another thread
http://www.peachparts.com/shopforum/showpost.php?p=2321618&postcount=10


Charlie

[wtsane]

First, thank you for the input. The springs/ride height were not something I had considered (law of unintended consequences I suppose). My springs are pretty soft, and I was considering progressive rate springs further down the road, but if the manual is going to alter geometry, I think your advice to use 240 fronts is spot on.

The rear diff is going to need some love at some point (loud-ish) but it is my intention to keep the 2.88 (highway mileage). I understand your point about the long spacing between gears, but it doesnt sound like anything I cant live with.

Again thank you for the advice, I hope this comes off.

[winmutt]

Skip the 240D springs and just lop a 1/2-1 coil off the stock springs. You will need a klann type spring compressor. You will find the 300D fw to be the smoothest but hard to find. Also try to get a DS dampener. Plan on replacing the DS center carrier bushing. Use loctite on the flex disks. Make damn sure you leave the 85 adapter plate on, its been 4 years since I had a tach

As far as the pilot bearing. I just milled mine down until it fit. I would NOT mess with the crank. Messing up a bearing is cheap and easy to fix. Crank not so much.

You will need 2 extensions and u join to get to the top bolts on the crank housing. When installing the trans its easiest to do it at a 90 or so angle so that the starter wart is pointing down. They dont mention it in the manual anywhere but every pic shows them doing this. Once the input shaft is in the engine rotate back up and bolt on. I would not bother with a trans jack with the manual if you have the stength.

PS remove the longitudinal shaft on the IP linkage coming from the firewall to save from having to buy a new pivot joint for the linkage.The engine will be tilting for and aft.