Jump to content
  • When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

4-speed Transmission compatibility late to early


jdt10768

Recommended Posts

1970 4-speed 2002 vin 1674882: My transmission is a bit crunchy when shifting into different gears. Unless I'm at the perfect speed / rpm it grinds a bit going into the next gear. Maybe that's normal, but I don't think it should be. It doesn't jump out of gear, just a little grinding.

My question: Is a later model (1974) 4-speed transmission a direct fit replacement for the existing early model 1970 4-speed trans?

1970 Agave work in progress

Born on May 14 1970 and delivered May 19th 1970 to NYC to Hoffman Motor Corp. Agave code 071

new guy

help appreciated!

other cars: 1991 318is / 1999 540iT

Link to comment
Share on other sites

Quote

If you get the chance, run the shifter mechanism that comes with the earlier trans. 

 

Andrew and I disagree about this.  But that's ok.  He's wrong. ;)

 

Opinions aside, with a 1970, you run a chance of having the old style synchros.

They shift great, but not for long. They will make you a better driver.  The later style

shift more smoothly.  And last a lot longer.

 

The one other thing to think about- if you're graunching all shifts, you might have clutch trouble.

Or clutch hydraulic problems.

If it's just not going cleanly into 2nd, it's most likely the trans.

Either way, you'll have it apart, and clutches don't cost all that much.

 

t

 

 

  • Haha 1

"I learn best through painful, expensive experience, so I feel like I've gotten my money's worth." MattL

Link to comment
Share on other sites

Thanks guys, I always like several opinions and your disagreement makes me smile - maybe more of a smirk

 

Truly, the situation is not that bad. And if I concentrate on making clean shifts I can do better. But there are times when I just expect it to shift cleanly, and it doesn't - maybe because I'm in a hurry or at wrong RPM etc

All shifts are not graunchy, just sometimes. And it's not horrible grinding, but just a quick feedback from the trans of an unclean shift 

 

I'll just try harder to shift at the right time / RPM 

1970 Agave work in progress

Born on May 14 1970 and delivered May 19th 1970 to NYC to Hoffman Motor Corp. Agave code 071

new guy

help appreciated!

other cars: 1991 318is / 1999 540iT

Link to comment
Share on other sites

+1 for Toby....I have found that if you mix dexron ATF and GL-4 in a 50/50 blend it seem to work very well when the trans is cold and hot.  It also helps with shifting and cleaning out the box.  I was taught this, by the late Peter Delott.  my humbling $.02 cents worth.

Matt

 

To check your clutch hydraulics.... while stopped in neutral, press the clutch, shift into a gear, and hold for a little while, if the rpm's begin to drop without releasing the clutch pedal.  Then faulty clutch system.

Edited by Schnellvintage
additional info
Link to comment
Share on other sites

Coupla things...I've had very good experience with using RedLine MTL in both my '02s--the '69 with those fragile but oh-so-smooth Porsche type synchros, and the '73 with the much more robust but notchier Borg-Warner synchros.  

 

The Red Line made that 2nd gear downshift on the '69 much smoother (although mine has nearly no grinding after 49 years because I've babied it since new, knowing its fragility from the get go), and it took all the notchiness out of the 73's shifting.  

 

2 hours ago, Schnellvintage said:

To check your clutch hydraulics.... while stopped in neutral, press the clutch, shift into a gear, and hold for a little while, if the rpm's begin to drop without releasing the clutch pedal.  Then faulty clutch system.

Just want to be sure you know that Schnellvintage is saying that failing this test means you have a problem with your clutch hydraulics, not the clutch itself...

 

mike

'69 Nevada sunroof-Wolfgang-bought new
'73 Sahara sunroof-Ludwig-since '78
'91 Brillantrot 318is sunroof-Georg Friederich 
Fiat Topolini (Benito & Luigi), Renault 4CVs (Anatole, Lucky Pierre, Brigette) & Kermit, the Bugeye Sprite

Link to comment
Share on other sites

1 hour ago, Schnellvintage said:

Sorry I had 3 Manhattans (Bullet bourbon ?). When I posted last night

Were these single cherry or two cherry?

  • Like 1

A radiator shop is a good place to take a leak.

 

I have no idea what I'm doing but I know I'm really good at it.

Link to comment
Share on other sites

Will try fresh fluid and report back, thanks

1970 Agave work in progress

Born on May 14 1970 and delivered May 19th 1970 to NYC to Hoffman Motor Corp. Agave code 071

new guy

help appreciated!

other cars: 1991 318is / 1999 540iT

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • BMW Neue Klasse - a birth of a Sports Sedan

    BMW Neue Klasse - a birth of a Sports Sedan

    Unveiling of the Neue Klasse Unveiled in 1961, BMW 1500 sedan was a revolutionary concept at the outset of the '60s. No tail fins or chrome fountains. Instead, what you got was understated and elegant, in a modern sense, exciting to drive as nearly any sports car, and yet still comfortable for four.   The elegant little sedan was an instant sensation. In the 1500, BMW not only found the long-term solution to its dire business straits but, more importantly, created an entirely new
    History of the BMW 2002 and the 02 Series

    History of the BMW 2002 and the 02 Series

    In 1966, BMW was practically unknown in the US unless you were a touring motorcycle enthusiast or had seen an Isetta given away on a quiz show.  BMW’s sales in the US that year were just 1253 cars.  Then BMW 1600-2 came to America’s shores, tripling US sales to 4564 the following year, boosted by favorable articles in the Buff Books. Car and Driver called it “the best $2500 sedan anywhere.”  Road & Track’s road test was equally enthusiastic.  Then, BMW took a cue from American manufacturers,
    The BMW 2002 Production Run

    The BMW 2002 Production Run

    BMW 02 series are like the original Volkswagen Beetles in one way (besides both being German classic cars)—throughout their long production, they all essentially look alike—at least to the uninitiated:  small, boxy, rear-wheel drive, two-door sedan.  Aficionados know better.   Not only were there three other body styles—none, unfortunately, exported to the US—but there were some significant visual and mechanical changes over their eleven-year production run.   I’ve extracted t
  • Upcoming Events

  • Supporting Vendors

×
×
  • Create New...