4:88's installed- A few questions for the future!

[93toy]

Okay, I've researched "speedo gear" on here but still haven't found my answer. I've got a 2.7 5 speed and just got 4.88's installed. Currently running 33's and the speedo is 10mph too fast. Now from what I've read, on my truck (a 1997 BTW) a 33 tooth speedo gear would be nearly perfect speedo correction for 33 inch tires. But I'm likely going to go with 35's soon. Considering the 35's will slow the speedo down, do you think it will be pretty accurate at that point or will I still need to change speedo gears? Anyone else have 35's and 4.88's in a 2.7 5 speed that could answer this?

[StealthTaco]

i've got the 3.4 and my speedo is off by like 8. I heard from somewhere before that when I put on the 35's it'll be like stock. I have 285/75/R16, basically a small 33.

[jon_7248]

I have 285/75/R16, basically a small 33.

Actually that's a true 33! Because most 33x1250 tires are actually 32.4 or 32.6 or something like that. They are rarly made to be 33"s. You have a true 33.

[hytenor]

there are 5 speedo gears available from Toyota, 28, 30, 31, 32 and 33 tooth. but...they are not all interchangable especially for gen 1 trucks ('95.5-'97). However, they can be made to work with a little care and finese. The gear shafts are different lengths but the plastic gear can be swapped with care to make it work.
cost is about $20 from Chris in Dallas.

the first thing you need to do is establish how far off your speedo is now.
then pull the speedo gear and find out how many teeth it has.
each tooth corresponds to approx. 3% error correction. So, if you are 10mph off you'll need 3 more teeth to get closer to stock. If you have a 30t or less gear you will be able to get pretty close but if you have a 32 you are sol.

As for going to 35s with your 2.7 and getting back to an accurate speedo, it will depend on what OE gears you had.

the only way to get perfectly calibrated is to go with the Dakota Digital (all year Tacos) or the Sky jacker unit ('95.5-99). The Dakota is about $80 and the other is $160.

[93toy]

Thanks guys. Some good information to go on.

[hartzpad]

How is the 2.7 with the 4.88's? I've got a 2.7 that I'm lifting soon and I plan to run 33x10.5's on 15x7 wheels. I plan to go with 4.88's and would like to know how the RPM's are on the freeway at 70 and how the power is around town? Do you feel that 4.88's are perfect?

[Oppositeboy]

Okay, I've researched "speedo gear" on here but still haven't found my answer. I've got a 2.7 5 speed and just got 4.88's installed. Currently running 33's and the speedo is 10mph too fast. Now from what I've read, on my truck (a 1997 BTW) a 33 tooth speedo gear would be nearly perfect speedo correction for 33 inch tires. But I'm likely going to go with 35's soon. Considering the 35's will slow the speedo down, do you think it will be pretty accurate at that point or will I still need to change speedo gears? Anyone else have 35's and 4.88's in a 2.7 5 speed that could answer this?

It should be pretty close with 35's. I have a 3.4L and my speedo was dead on with my 37" MT'R's (measuring 36.2" or 36.5"...I can't remember which).

[StealthTaco]

Oh, I guess it depends on the tire company. But yeah I just call it a 33.

[93toy]

At 70mph I'm turning about 2700-2800 rpm. The power is great around town, it doesn't get near as "winded" as it used to. Power all through the rpm range.

[hytenor]

How is the 2.7 with the 4.88's? I've got a 2.7 that I'm lifting soon and I plan to run 33x10.5's on 15x7 wheels. I plan to go with 4.88's and would like to know how the RPM's are on the freeway at 70 and how the power is around town? Do you feel that 4.88's are perfect?

I have the 2.7 with 4.88s (5-sp) and they are great. But, if I only did hwy all the time, didn't wheel much and didn't haul a ton of wood every now and then I would have stuck with the 4.56s that I used to have.
70 is around 2800 in 5th. rpms will be less with the AT since the top gear is taller.
around town mileage actually went up a tad. hwy mileage went up as well but only if I keep in under 70. overall mileage increased by about 1.5 mpg going from 4.56s to 4.88s. the difference in 4-low is huge and that really surprised me.

[My68ur8trd]

i got a 33 tooth gears in the sendor still. i got it up on ebay at the moment.

Justin

[My68ur8trd]

nevermind i cant count :banghead:

Justin sorry