Getrag & 3.07 Gears part II

[Doug Czaja]

Finally got the Dana 70 with 3. 07's swapped into my truckOo. Took about 6 hours mostly by myself. Went for a test run & I LOVE it . No more howling from the rear end. The noise I thought was coming from the transmission is all gone . Passed a car on the test run .



I would again like to thank all who have had experience with this type of swap & were good enough to share there advise .



As usual, now for the question. Guessing that my speedometer is indicating around 20MPH slower than the actual speed. Where can I find the gears to correct the error? It is 4:30 on a Saturday afternoon, so unless you good folks have any advise, I will start calling speed shops on Monday.



Thanks,

Doug

 

[Thierry]

DCzaja, I am happy to see another 3. 07 convert, good going, glad you got the rear end in, been there in the same shoes.

You need to get a new pinion for your transfer case Mopar part # 2538926, this will correct your speed If you pull your pinion out and were running 3. 54 you should see that it is a # 2538930

You cn get the Mopar man to verify this number will work in you application, I seem to remember the price of $27 dollars



Now question for you is how are you going to adjust you front end, did you get some 3. 07 gears for the front????





Thierry

 

[Philip]

I will start calling speed shops on Monday.

Speed shops won't have this item. You need to hit a Dodge dealer. You need the drive gear inside the trans. Just tell them your axles ratio and if they happen to ask for tires size just pick the one closest to what you have on the truck.



If you do not have a manual when you find the speedo drive gear be sure to ask here how to set the gear in. It has a cirten way to be installed or you will stripe it out.



I have the 3:07's also. Nice gears aren't they.



Thierry got in a fw seconds before me. Glad you had the numbers.

 

[Thierry]

Makes it real easy when you have the old hard copy parts manuals for our trucks



Good luck and happy driving

Thierry

 

[Doug Czaja]

Thierry / Philip,



Thanks for the tips & part number guys. I'll give the dealer a call Monday for the speedometer gears.



I am very happy with the gears so far, wish I would have done this a long time ago. Another bonus to this axle is that the brake drums are MASSIVE . The truck is actually breaking better now than ever before Oo. . Can't wait to get the speedometer error corrected so fuel mileage can be calculated.



Thierry, still haven't found a Dana 61. I'll just keep out of 4X4 until one surfaces.



Thanks again guys,

Doug

 

[dpuckett]

DCzaja,



Another option is getting your adaptor box rebuilt. Had to do that in my 91 when the input shaft on the factory box broke, and dealer wanted $110 for a new one. Went to a speedometer shop in ColoSprings, and he made me a new one for $50 or so. Put your speed sensor in directly to the threaded part coming out of the transmission (in other words, remove the gear adaptor) and see how much over/ under you are after covering a known distance. If you're interested, PM me, and I can give more details. New box gives better accuracy than new gear. Ratio on mine is . 5607 or something like that.



PS- going from 4. 10s to 3. 07s, your speedo will be 25% slow. IE- If speedo says 45, you're going 60; at "30," you're really doing 40. Add 1/3 to what speedo says. It will make MPGs stink until you get it changed.

Daniel