differential ratios

I have an 86 B2000 and one of the rear wheels has a slight wobble. (yes, it is the axle shaft, not the wheel) Since I am going to replace the whole axle, do any other Mazdas have a better gear ratio in the axle than the B2000? I want something that will rev lower on the freeway.

Pre 85 Mazda and Courier. Its also narrower and will tuck any wheel with a bodydrop. Get the driveshaft too. On a standard cab you have to shorten the driveline about 5.65".

According to the info I found on Mazda truckin.com it looks like all the 86-93 axles were a 3.90 ratio regardless of transmision type.

I think the B2600 and B2600i 2wd has 3.23 gears and its the same rearend

hehe, 3.23 gears whoever told you that one was on crack.

The B2600i 4x4 models have a 4.300 gear in the manual transmissions and a 4.444 in the automatics. Front and rear are the same.

All The B2600i 2wd has a 3.727 which would probably be pretty good. All your 86-93 B2200s have 3.909. The 84 B2000 has a 3.308. I don't know what the B2600s with the mitsu engine have off the top of my head.

I would not recommend going to a lower ratio diff unless you have done some engine mods though. It is going to decrease you're acceleration making it even more of a pig to drive. But if you're still going to do it the diff out of a 2wd B2600i is the one I would recommend. I believe for that diff you have to remove the ring and pinion and transfer them into your B2200 casing though as it's not a "bolt in" swap.

I agree. People who want to "lower their freeway rpm" are used to american V8's with lots of torque at low rpms.

Your cruising engine speed should correspond to the torque peak of the engine. If you select too low (numerically) a gear, the engine will not be near its torque peak and you will use MORE gas because the engine is working harder to maintain speed. If your engine is near the torque peak at cruising speed, you will be able to climb hills without a downshift because the engine is operating where it is most efficient. As an example, I have a lightly opened up (low restriction air filter, meowless exhaust) 318i. The final drive ratio is 4.10 and at 77 mph I am turning 3600 rpm. At that rpm I get ~35 mpg. Installing a 3.73 would KILL that mileage.

Yes, or for another example when I baught my truck my best gas mileage was around 21 or 22 at about 60 mph. I do most of my driving on the interstate and the interstate speeds run 70 to 80 mph around here. At those speeds the engine was revving too high and causing it to get 18-19 mpg especially if I had to do a lot of downshifting on that tank of gas. So because of that (and some other reasons) I decided to put a japanese miata tranny in my truck. Now if I'm cruising at around 60-65 mph I'm getting about 18 mpg but at the speeds I normally travel around 70-75 mph I'm getting about 21. I really didn't gain anything I just optimised it for the way I drive it.

My truck probably makes it's peak torque about 600-800 rpm less than Russd's given his crazy intake setup. So what works good for him would absolutly kill mine.

Originally posted by pearldrop



I have an 86 B2000 and one of the rear wheels has a slight wobble. (yes, it is the axle shaft, not the wheel) Since I am going to replace the whole axle, do any other Mazdas have a better gear ratio in the axle than the B2000? I want something that will rev lower on the freeway.



Yes you can use any RX-7 pre 1985 rears..with the 1983 and older you will have to use your LSD or carrier.

Hey i have a b2200 rear out back..i will let it go real cheap..pm me..

So the overall consensus is to keep the stock ratio?

I'm sure having smaller tires than stock has worsened the problem (195/50/16) but I swear the truck sounds like it is at 5000 rpm on the freeway at 70-75. I don't mind high-revving engines, I have driven Hondas most of my life. I just hate driving it on the freeway because there is so much road and engine noise. I was hoping to at least cut down on one of those.

Do the B2200s have a differently geared transmission than the B2000s? I think this truck feels too low-geared all the time. I start in second gear half the time.