Replacing transmission

waynek · Post by **waynek** » Tue Nov 09, 2004 4:51 am

I'm thinking about replacing the transmission in my 1974 Thing.It's
original and as we all know it's geared lower.I wish to improve on the
top end for highway driving.I can get a transmission from a 74 Beetle
and I'm wonder what the verdict will be on performance if I put it in
my Thing.Also, I beleive it's a straight swap other than changing the
nose cone.Please correct me if I'm wrong.

Thanks to all

suntour · Post by **suntour** » Tue Nov 09, 2004 6:53 am

Waynek,

I run a stock Bug transmission in my Thing and it works fine for running around town. When you swap a Bug transmission to a Thing you don?t need to change the nose cone, however you do need to swap the flanges for the drive lines. Things use much larger and better CV joints than Bugs. Just pop off the retaining clips that you will find under a mountain of old grease when you remove the drive lines and the flanges should just slid off. (Or if they are stubborn just motivate them with a rubber mallet) Swap the Thing flanges to the Bug Trans and reinstall. (Don?t forget to replace the retaining clips after you make the swap.)

As long as you?re at it, you might also consider cleaning the CV?s and repacking the grease and replacing the CV boots if they look worn. Also check the Transmission mounts for damage and wear and the clutch cable sleeve.

I find that the bug transmission is fine for driving around town but you still don?t get an amazing top end speed. It is better though. Let?s face it stock-ish Thing?s just aren?t that fast.

Bob Ingman · Post by **Bob Ingman** » Tue Nov 09, 2004 8:58 am

Good advice Justin.
Waynek be sure the trans is good before installing it so you do not end up doing a lot of work for nothing.
Drain it paying attention to the amount of metal in the lube and on the magnetic drain plug. Use the fill plug on the side to look in a paak at the gear cluster to make sure there are no surprizes. Good luck. Bob Ingman

http://www.geocities.com/Baja/Dunes/9702/transtalk.html

Bruce2 · Post by **Bruce2** » Thu Nov 11, 2004 2:25 am

The Bug trans won't do anything for you. The final drive ratio of the Bug trans is virtually the same as the Thing. The real difference is in 1st through 3rd gear. Those are taller.
Bug: 3.875 x .93 = 3.603:1
Thing: 4.125 x .89 = 3.671:1
The difference on the road is 1.9% In other words, if you are going 60mph with your Thing trans, switching to a stock Bug trans will have you going 61.1mph at exactly the same rpm.

If you want higher cruising speed, go to a taller tire. 15" wheels would do the job.

caspar · Post by **caspar** » Thu Nov 11, 2004 2:12 pm

cant u have ur thing trans. rebuilt for a higher 4 th gear ratio????
or what about this highway flyer i keep hearing about?? anybody heard of these???

caspar

Post by **Marc** » Thu Nov 11, 2004 2:21 pm

You could put a .82 (bus) 4th into a 4.125 trans - that's the combination usually referred to as a "freeway flyer". At 8½% taller, that'd make about a 5mph difference at the same RPM. I'm not sure if it's wise though, a Thing is about as un-aerodynamic as you can get and you might end up short of horsepower to push it with the taller gearing. There are situations where the wider spread between 3rd and 4th might not be desirable, too. Try Bruce2's suggestion first - run some tires that are ~8% taller for a while to see how you and the engine like it before investing in a different transmission.

suntour · Post by **suntour** » Thu Nov 11, 2004 4:19 pm

I do have the ?freeway flyer? gearing in my transmission and I run 15? rims with 205 R60?s, they are around 25? so they are close to stock size and only powered by a 1776 (D.O.A. as of yesterday). You can feel the strain on the engine when you first shift into 4th gear and even with this I top out around 70mph for cruising speed. Like I said earlier in the posts, you just don?t get amazing speed? Things just aren?t that fast?

I have also found that you can?t get much bigger tires than that under the fenders with a stock suspension. Last time I squeezed a larger set in there with stock suspension height I ended up with custom flared rear fenders when I bottomed out the suspension. Oops?

Bob Ingman · Post by **Bob Ingman** » Thu Nov 11, 2004 7:36 pm

The best way I have found for increasing top speed is by increasing power. Not by gearing up with a small overworked engine. When I had the stock thing enngine in my car using a T-4 1911 engine it would quickly get to 70 mph in third gear. Dropping into forth was very relaxed after that and 70-80 was easy cruising.
Thing about engine changes as opposed to trans changes for more top end. Good luck. Bob Ingman.

waynek · Post by **waynek** » Sun Dec 12, 2004 9:13 am

Thanks all for the feedback.
The bug transmission I have as a spare is an AT and the Thing
currently has a AV.
Running 14" tires at the moment.So I guess 15" are the way to go.
Can someone do the mathmand tell me if there is any difference at
all between these transmission, performance wise.

Bruce2 · Post by **Bruce2** » Sun Dec 12, 2004 10:59 pm

Go up and read the 4th post in this topic.

Kubelmann · Post by **Kubelmann** » Tue Jan 04, 2005 5:08 pm

MPH = RPM x tire diameter in inches/drive ratio x 336

drive ratio =ring and pinion ration x gear ratio

Now get final drive ratio from Bruce2's earlier post

K-mann

Kubelmann · Post by **Kubelmann** » Tue Jan 04, 2005 5:28 pm

To calculate metric tire diameter you must know what the numbers mean.

A 195 65 15 tire is 195 mm wide

the tire from the wheel opening to its edges is 65% of 195mm

The wheel size opening is 15" to get mm multiply by 25.4

or 15 x 25.4 = 381

To get the diameter you must take 195 x .65 x 2 + 381

or 195 X .65 =126.75 x2 = 253.5 +381 = 634.5 / 25.4 = 24.98"

I built a few different gear ratio/ tire size calculator as an excel spreadsheet that is included as part of the RoMTOC Thing Data CD. It goes for $10 directly from me or you can get it from Things Unlimited directly from their web site. K-mann