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View Full Version : Is your speedometer off? Try the Superlift Truspeed.



Difranco
05-03-2008, 02:15
My Problem:

After going to tires larger than stock (31" to 33") this change made my speedometer 7% off. Well I lived with this for quite sometime and just did the math in my head for actual speed. However my Jeep is an Automatic ( I love it! ), my transmission shifted slightly off. Well to overcome the loss in power of driving up hill (long mountain passes), which I do a regular basis I decided to have my jeep regeared with 4.88's which was a steep drop from the 4.10's I was running previously. Lastly this just put my speedometer reading 10-15 MPH over actual speed at 55 MPH. This really screwed up my shifting and was definitely eating into my gas mileage.

First attempt at a fix:
My jeep has the trac rock transfer case w (NV241OR) which means that I can't just change a speedometer gear to fix my speedometer but have to take it into the dealership have them program the computer for the correct tire/gear ratio. $55.00 later I found out that they couldnt program my system for the tire/gear ratio I had so they set it to 33/4.56 which helped some but was still not much of an improvement.

The Actual fix:
Well after delving deep into the dark nether reaches of the internet I came across a product that seemed like it would resolve all my issues and life would be grand again. The Superlift Truspeed (http://www.superlift.com/accessories/truspeed.asp) seemed to be about the only option I could find, so I ordered one up from Northridge4x4.com (http://www.northridge4x4.com/).

Install is pretty straight forward. I spent more time planning the install and calibrating the TrueSpeed than actually connecting everything up.

After all is said and done my Jeep's Speedometer reads exactly 60 MPH when the vehicle is traveling 60MPH as calibrated by my Garmin 60CSx GPS unit. I noticed an immediate improvement in shifting, and by the end of the week I will know if my MPG has improved.

Tomorrow its new brake pads, rotors turned, brake fluid flush and Oil change.

Ciao,
Difranco

korisu56
05-03-2008, 03:53
Lookin good. I had never even heard of this. I'm sure a lot of automatic drivers out here will love it.

Hitechredneck
05-03-2008, 05:58
I have heard problems with tis and having interference with something with while you are talking on your cb. I dont have one myself but there are a few post on ROF talking about it. I guess the fix is to wrap the unit in tin foil and that fixes it. Just wanted to throw this out there in case some sillyness happens with yours or others that install it.

miljeep
05-03-2008, 10:04
I am going to look into this, thanks. I am also going to hop over ot ROF and see what I can dig up about this and the issue with the CB.

Difranco
05-03-2008, 11:09
Doesn't seem to affect everyone's CB http://rubiconownersforum.com/phpbb3/viewtopic.php?f=31&t=57078

miljeep
05-03-2008, 15:42
Thanks for the link. I have the same CB as that one guy on that post, so I am going to look into getting this and seeing how it works.

Difranco
05-03-2008, 21:04
Tested my CB no more noise than there was before.

Difranco
05-06-2008, 19:30
***Update***

Drove past a Sheriff's Office radar speed check trailer like this one:
http://www.public-safety-systems.com/images/speedtrailer.jpg

in a 40 MPH zone and my speedo was dead on!

korisu56
05-06-2008, 19:43
That's really good to hear. I'm really glad that you came back and told people how it worked out for you.

Difranco
06-20-2008, 01:21
Someone somewhere asked me I think on this board what my MPG was with 4.88's / 33's and the 6cyl/auto. Well now that my gears are broke in I've seem to settle into about 15 MPG average, which is in EPA spec of a stock TJ Auto.

USMCHarleyJeepGuy
06-20-2008, 07:52
A lot of things will cause electrical noise in a CB base on how it is set up. Best way to avoid it is to pull your hot side for the radio directly from the battery or an isolated circuit from the ignition, ecm, and tranny computers. If you run it through a circuit boss or directly from the battery via an inline fuse, you will cut the majority of the noise out of the system vice running through a fuse block tap or the cigarette lighter/power point. :cool:

Just a little FYI (hopefully it will keep you from wrapping your components in tin foil...or the next thing you know, you'll be wearing a tin foil hat so "They" can't steal your thoughts just like Yeti!):eek::D

lifejeep
06-20-2008, 21:06
any ideas on how to calibrate my speedometer without taking in and paying someone?

USMCHarleyJeepGuy
06-20-2008, 21:11
any ideas on how to calibrate my speedometer without taking in and paying someone?

In your 2003 Bling-J? Just swap to the correct speedo gear. Cost you 10 minutes and 25 bucks.

lifejeep
06-20-2008, 21:23
"Bling-J" is this your handy nicknaming again...................thanks for the info

05warrior
06-21-2008, 23:28
any ideas on how to calibrate my speedometer without taking in and paying someone?

This should help you out.

http://www.4x4xplor.com/speedo.html

Don't worry about USMCharleyjeepguy, he's just jealous his wheels aren't as pretty as yours.:D

healerdoc1
06-22-2008, 04:47
Thanks for the info, I need to correct ours...

Ghost00TJ
06-22-2008, 10:10
Someone somewhere asked me I think on this board what my MPG was with 4.88's / 33's and the 6cyl/auto. Well now that my gears are broke in I've seem to settle into about 15 MPG average, which is in EPA spec of a stock TJ Auto.

I still have stock 3.07's and 33x12.50 tires I get just above 12mpg wit an AT and 4.0l. So a 3 mpg increase plus the better ride is a good thing.

E5EDDIE
06-22-2008, 23:45
Damn it's expensive! But, something I'm gonna put on the list for next year!