I'd like to lower my cruising rpms. The IRS in Speedy I believe is from the donor 69 --dual spring plates. If I swap out to say a 73-74 beetle trans--will the rpms be lower at at cruising speeds of say 65-750mph? Using the old CMC Vintage gauges still I'm running in the 3300-3500 range at 65 if I remember correctly--just a few times out last year. I really don't want to dump $1500 into a freeway flyer as I have access to a few trans I can grab for a fair price.
David
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I've posted this link before to the transaxle codes and what R&P gear they have. Not sure how accurate they are. I've yet to find an LSD code transaxle in US! So looks like '73 up gives you a good chance of the 3.88 R&P vs the more typical 4.1237. NOTE - the nose cone is different between '69 and '73 up so you will need to swap nose cones, buy an adapter (cheapest), or cut off old and weld on new style front support piece. I think someone said your top gear rpms would drop 200 rpms. This depends on your tire size - as low profile tires will increase rpm - the 200 rpm is with 165/80x15 tires.
http://www.midsouthvw.com/Tech...ip_TransaxleCode.htm
OLDER NEWER
Aircooled’s chart should be good to use in your search for a new gearbox.
Another approach might be either take your existing transaxle (if it’s in good shape) or one of those other ones (if it’s in good shape) and buy a 3:88 ring and pinion set from someone like Rancho and install it. If your engine is a 1915 or less it should be just fine.
Gotta be lots cheaper that way than a built-up freeway flyer if you can’t find a later, stock 3:88 box
When I went to a 3:88 box my rpms at 70 went down to about 3250 or so.
Running 1835cc with dual dell 40's. Tires are 185x65x15. Mine current one leaks at both covers so I'd rather reseal another to lower rpms. Guess I'll be looking at some serial numbers this week and do some comparing with the chart-Thanks
@WOLFGANG wrote- "I've yet to find an LSD code transaxle in US!"
I'm of the understanding North America never got any cars with lsd equipped transaxles, Greg. That's why they're so hard to come by here.
@Heritage 2008- Remember that any trans you find is 40+ years old and probably rebuilt at least once (and any combination of parts could be inside), so if you're looking for a later trans hoping to find a 3.88, stipulate that you are able to pull the side cover to verify the r&p is the expected ratio. Also note that a 3.88 trans out of a Beetle will probably be different than one out of a Karmann Ghia- the Beetle trans will have a .93 4th gear which gives the same final drive as a 4.125x0.89 combo, which is probably what you have now. The 3.88 Ghia trans, otoh, will have the longer 0.89 4th, but they are harder to come by, as there weren't nearly as many Ghias as Beetles. The longer 4th can be fitted to the Beetle trans, but it requires a full teardown.
Ideally you'd like to find an unmolested single side cover Ghia transaxle, and if it had the (stronger) offset top webbing on the case, all the better. Look at the webbing over the differential area on the left trans-
I could be completely wrong, but I'm with Al. I wonder how many engines or transaxles are left out there that have never been cracked open since they left the fatherland 50+ years ago. I would guess the number is vanishingly small.
I have a couple unmolested IRS trans. I opened one and it looked (and smelled) untouched. However they are 1970-71 so they both have the 4.12.
I'm with Gordon's response to an extent. You probably want to check and refresh the innards rather than just swap the ring and pinion. Swapping the pinion shaft is a VERY necessary part of the ring gear swap, they go together. In order to swap the pinion gear you must completely disassemble the transmission, and swap all the gears to the new pinion shaft. If it is a different style, and there are several, you may be dead in the water, especially if you don't know what you're looking at. At that point you'll need parts and spares. And to install it requires knowledge and special tools to shim the R & P properly. Synchros are cheap, change them. Teeth profiles must be checked as well as bearings. Careful assembly respecting clearances is the only way to assure a good-working unit.
Al: us Spyder guys need the double side cover cases due to the flipped ring gear, so I never even look at single side covers......
At this point it starts to make sense to buy one from a reputable rebuilder then ship them your core. Unless you have a local guy that can rebuild and change parts in YOUR trans.
And if you get a later trans with 3.88, swap the nose cone to an earlier style. They are available brand new for about $40. Anybody should be able to accomplish that swap.
If it was me I would think about the whole engine tranny combo and see if any upgrades were wanted in the future like a 2110cc. If that is true then watching Beck or others who do engine swaps might give you an engine tranny combo that fits your needs. 2210cc with a 3:44 R&P is a great combo IMO.
No engine swap or interested in dropping $5000 into Speedy. Just looking for a 1973+ original trans to make the swap. Thanks for all the ideas guys.
They're getting harder to find all the time. Managers of salvage yards either want to bring in cars really cheap, prep them (drain fluids and remove wheels) and then crush them for transport to Asia for recycling, or bring in something in the range of ten to twenty years old to use for salvage parts. VW Beetles don't fit that criteria so they've been getting scarcer for years. Good luck with your search - some are still out there....
Remember what I said above- a Beetle 3.88 trans will have the 0.93 4th gear, making it almost exactly the same final drive as 4.125/0.89 (3.60 vs 3.67). The Ghia trans (3.88/0.89- 3.45 final drive) has what you're looking for, but they're not exactly plentiful, so it's still going to cost a trans rebuild. Here's what the 2 look like-
http://www.teammfactory.com/ca.../0/0/3600/3600/1/0/2
You'll notice that 1st, 2nd and 3rd gears are slightly longer with the 3.88, but with the 0.93 there's only 2 mph difference at 35-3600 rpm. Click on the 4th gear box in example 2 and input 0.89, click outside the box, click on 'Calculate Transmission 1&2' and note the difference in 4th gear now.
Stan Galat posted:I could be completely wrong, but I'm with Al. I wonder how many engines or transaxles are left out there that have never been cracked open since they left the fatherland 50+ years ago. I would guess the number is vanishingly small.
You are right, Stan, you can still find an original factory trans occasionally in someone's stash, but you've gotta put in the time looking. As I've said before, the snow belt (where cars actually rust out before a lot of parts wear out) is where you'll find unmolested stuff in people's stashes.
DannyP posted:I have a couple unmolested IRS trans. I opened one and it looked (and smelled) untouched. However they are 1970-71 so they both have the 4.12.
Al: us Spyder guys need the double side cover cases due to the flipped ring gear, so I never even look at single side covers......
Yeah, I get that, Danny, but that's where you find the stronger 9 tooth 3.78 mainshafts (and no, they're not 'Super Beetle" mainshafts- they came in everything once they were introduced) vs the older 10 tooth 3.8's. Mind you, your car is so light it probably doesn't matter. If you do find a nice ssc case with the zig-zag top and a double ring side cover those alone are worth a few bucks, so you'll make your money back.
Al that is probably why a lot of people just swap the R&P to a 3:44 and keep the rest the same with a 2110cc engine or subie.
Heritage 2008 posted:I'd like to lower my cruising rpms. The IRS in Speedy I believe is from the donor 69 --dual spring plates. If I swap out to say a 73-74 beetle trans--will the rpms be lower at at cruising speeds of say 65-750mph? Using the old CMC Vintage gauges still I'm running in the 3300-3500 range at 65 if I remember correctly--just a few times out last year. I really don't want to dump $1500 into a freeway flyer as I have access to a few trans I can grab for a fair price.
David
Then your only cheap option is to increase your tire height. I could go on and on and on about gear ratios - just ask ALB!
2nd cheapest option, IMO, is to find a good transaxle with a stock .89 4th and swap the 3:88 ring and pinion with a 3:44. That will put you close to 3000 rpms at 70 mph without the tremendous rpm drop that you get between 3rd and 4th on a freeway flyer. @IaM-Ray Yes!
Here we go again...
I think Stroud just bought tallish (i.e. normal height) tires. 3.44 + .89 would get him 75 mph @ 3000 rpm. The .93 4th gear would be 70 mph.
Swapping in a new ring gear is gonna be like $800 though, all said and done.
If your changing the engine it is worth it.
Heritage 2008 posted:I'd like to lower my cruising rpms. The IRS in Speedy I believe is from the donor 69 --dual spring plates. If I swap out to say a 73-74 beetle trans--will the rpms be lower at at cruising speeds of say 65-750mph? Using the old CMC Vintage gauges still I'm running in the 3300-3500 range at 65 if I remember correctly--just a few times out last year. I really don't want to dump $1500 into a freeway flyer as I have access to a few trans I can grab for a fair price.
David
Contact Noel Farmer on this sight. He may sell his freeway flyer (swing axle) soon.
