Tranny RWD conversion

Kerry Phillips · 02-13-2009, 11:27 AM

Hello!

Okay, I am about finished with my conversion. Have a problem. The shift linkage that is connected with two bolts on top of tranny-the part that pivots-the "stud" is about 1" too high, thus not fitting inside of the "dogears" on the selector shaft. The metal bar is almost perfectly flat, I am going to try to bend it. Has anyone have/had this problem? Is the bar suppose to be flat? Any comments/suggestions?

Other then this foul up, the conversion was relatively easy. The original selector shaft was bent, so it was replaced. Did not have the flange to mount the shaft seal, a few layers of JB Weld solved that problem. The shaft is 14mm, a 9/16" drill is 14.2x MM, so I used 9/16" bit. I swapped ALL the external accessories.

Ideally when/if this silvertop is completed, I am projecting 40MPG. The tranny's final top gear ratio is 15% higher-lower RPM's.
TNX
Kerry

muffinman · 02-13-2009, 11:36 AM

This may or may not be of some help to you
MKI MR2 Write-ups

ebouwman · 03-07-2009, 11:15 PM

what tranny are you doing this conversion to?

Kerry Phillips · 03-08-2009, 12:08 PM

The tranny came from a 1994 Geo Metro-only had 5K miles and was shiney, and only $250! The car had the 7AGE, I think..... The gear ratios are different based on what engine was in the car, I made sure at the time the transaxle had the 3.73 Differential. This is 15% drop in RPM over the 4.33diff. Fortunately, first gear is 15% lower, so the overall gear ratio remains unchanged for first, while 2-5 are changed. The 1-2 Shift might be a little more dramatic.

I solved my problem by heating up the flat metal bar and bending it.

I am off from work for three weeks (Unemployment = paid vacation time) and my one week off from school at the same time! Time to play Mr. Goodwrench.

I read some claims of 42 MPG for some MR2 MK1's, and that the Silvertop is more fuel efficient then the 16V. So with the new gear ratio, moderate cruising speed, and maybe the Honda Civic ignition upgrade...... Ideally I will install an A/F monitor, I have an idea on how to lean out the engine, supposedly the 16V and its ECU ran a little rich, this might be why the 20V is more efficient?
The best MPG I had was about 34. On one trip I only averaged about 27, my thermostat got stuck in the open position during winter. I lost my heater and the engine ran rich because it never came close to reaching normal operating temperature.

toyotaspeed90 · 03-12-2009, 09:55 PM

you mean it came from a geo prizm with a 7afe? BIG difference... 7age doesn't "exist" stock..... metro does not have C series transmissions in them.

If you have a C series from a geo prizm, then all you need to do is have yours and the new trans side by side. Put both in neutral, unbolt the selector shaft from the new trans and pull it out. Unbolt the selector shaft and the cap from the mr2 trans. Drill a hole through the front of the FWD trans where you pulled the selector shaft in the old one (if you drill too deep it isn't a big deal... all that will happen is that the seal will push in too far and the dust boot won't slip over it). Install the mr2 selector shaft and use the stock cap to cap off the hole where the shaft came from for FWD.

Kerry Phillips · 03-16-2009, 12:53 PM

Yes, I believe it was a 7afe. The flange on the tranny was shorter then on the original MR2 Tranny. The Padandwheels highlighted on this phenonomen. They suggested fabricating an adapter, another sight mentioned that several had satisfactory results using JBweld. The JBWELD blob only holds the shaft seal-bubblegum would almost work.
87 MR2
91-92? Toyota Levin engine
94 Geo Tranny
Pieces from two other tranny's
Might as well get those Honda civic igntion coils.
Might try to use some Nissan/Mazda parts as well.....

toyotaspeed90 · 03-17-2009, 08:19 PM

I have no idea what you are saying.

All C series transmissions through 97 have the same bellhousing. The trans should bolt to the motor absolutely no problem.

Kerry Phillips · 03-20-2009, 06:48 PM

The tranny bolted up just fine.

The shift selector shaft protrudes from the OPPOSITE side on MR2's.

Padandwheels websites shows the difference between C52 and C56.

One has an extended flange, which can be drilled out to install a shaft seal for the RWD conversion. My tranny had the shorter flange.

02-13-2009, 11:27 AM	#1 (permalink)
Kerry Phillips Cage Fighter Join Date: May 2006 Location: Chattanooga, TN area Posts: 299 Thanks: 0 Thanked 21 Times in 21 Posts iTrader Rating: (0/0% )	Tranny RWD conversion Hello! Okay, I am about finished with my conversion. Have a problem. The shift linkage that is connected with two bolts on top of tranny-the part that pivots-the "stud" is about 1" too high, thus not fitting inside of the "dogears" on the selector shaft. The metal bar is almost perfectly flat, I am going to try to bend it. Has anyone have/had this problem? Is the bar suppose to be flat? Any comments/suggestions? Other then this foul up, the conversion was relatively easy. The original selector shaft was bent, so it was replaced. Did not have the flange to mount the shaft seal, a few layers of JB Weld solved that problem. The shaft is 14mm, a 9/16" drill is 14.2x MM, so I used 9/16" bit. I swapped ALL the external accessories. Ideally when/if this silvertop is completed, I am projecting 40MPG. The tranny's final top gear ratio is 15% higher-lower RPM's. TNX Kerry

03-08-2009, 12:08 PM	#4 (permalink)
Kerry Phillips Cage Fighter Join Date: May 2006 Location: Chattanooga, TN area Posts: 299 Thanks: 0 Thanked 21 Times in 21 Posts iTrader Rating: (0/0% )	What Tranny The tranny came from a 1994 Geo Metro-only had 5K miles and was shiney, and only $250! The car had the 7AGE, I think..... The gear ratios are different based on what engine was in the car, I made sure at the time the transaxle had the 3.73 Differential. This is 15% drop in RPM over the 4.33diff. Fortunately, first gear is 15% lower, so the overall gear ratio remains unchanged for first, while 2-5 are changed. The 1-2 Shift might be a little more dramatic. I solved my problem by heating up the flat metal bar and bending it. I am off from work for three weeks (Unemployment = paid vacation time) and my one week off from school at the same time! Time to play Mr. Goodwrench. I read some claims of 42 MPG for some MR2 MK1's, and that the Silvertop is more fuel efficient then the 16V. So with the new gear ratio, moderate cruising speed, and maybe the Honda Civic ignition upgrade...... Ideally I will install an A/F monitor, I have an idea on how to lean out the engine, supposedly the 16V and its ECU ran a little rich, this might be why the 20V is more efficient? The best MPG I had was about 34. On one trip I only averaged about 27, my thermostat got stuck in the open position during winter. I lost my heater and the engine ran rich because it never came close to reaching normal operating temperature.

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02-13-2009, 11:36 AM	#2 (permalink)
muffinman U-P-G-R-A-Y-E-D-D Join Date: Jan 2008 Location: Sunny South Florida Posts: 5,878 Thanks: 53 Thanked 282 Times in 271 Posts Blog Entries: 1 My Google Map iTrader Rating: (2/100% )	This may or may not be of some help to you MKI MR2 Write-ups

03-07-2009, 11:15 PM	#3 (permalink)
ebouwman Curve Hugger Join Date: Jan 2009 Location: BC Posts: 1,600 Thanks: 19 Thanked 51 Times in 51 Posts My Google Map iTrader Rating: (0/0% )	what tranny are you doing this conversion to?

03-12-2009, 09:55 PM	#5 (permalink)
toyotaspeed90 No Skills Join Date: Jun 2006 Location: Bellingham, WA Posts: 2,401 Thanks: 0 Thanked 148 Times in 143 Posts My Google Map iTrader Rating: (0/0% )	you mean it came from a geo prizm with a 7afe? BIG difference... 7age doesn't "exist" stock..... metro does not have C series transmissions in them. If you have a C series from a geo prizm, then all you need to do is have yours and the new trans side by side. Put both in neutral, unbolt the selector shaft from the new trans and pull it out. Unbolt the selector shaft and the cap from the mr2 trans. Drill a hole through the front of the FWD trans where you pulled the selector shaft in the old one (if you drill too deep it isn't a big deal... all that will happen is that the seal will push in too far and the dust boot won't slip over it). Install the mr2 selector shaft and use the stock cap to cap off the hole where the shaft came from for FWD.

03-16-2009, 12:53 PM	#6 (permalink)
Kerry Phillips Cage Fighter Join Date: May 2006 Location: Chattanooga, TN area Posts: 299 Thanks: 0 Thanked 21 Times in 21 Posts iTrader Rating: (0/0% )	Yes, I believe it was a 7afe. The flange on the tranny was shorter then on the original MR2 Tranny. The Padandwheels highlighted on this phenonomen. They suggested fabricating an adapter, another sight mentioned that several had satisfactory results using JBweld. The JBWELD blob only holds the shaft seal-bubblegum would almost work. 87 MR2 91-92? Toyota Levin engine 94 Geo Tranny Pieces from two other tranny's Might as well get those Honda civic igntion coils. Might try to use some Nissan/Mazda parts as well.....

03-17-2009, 08:19 PM	#7 (permalink)
toyotaspeed90 No Skills Join Date: Jun 2006 Location: Bellingham, WA Posts: 2,401 Thanks: 0 Thanked 148 Times in 143 Posts My Google Map iTrader Rating: (0/0% )	I have no idea what you are saying. All C series transmissions through 97 have the same bellhousing. The trans should bolt to the motor absolutely no problem.

03-20-2009, 06:48 PM	#8 (permalink)
Kerry Phillips Cage Fighter Join Date: May 2006 Location: Chattanooga, TN area Posts: 299 Thanks: 0 Thanked 21 Times in 21 Posts iTrader Rating: (0/0% )	The tranny bolted up just fine. The shift selector shaft protrudes from the OPPOSITE side on MR2's. Padandwheels websites shows the difference between C52 and C56. One has an extended flange, which can be drilled out to install a shaft seal for the RWD conversion. My tranny had the shorter flange.