'98 Power Problem

I have a '98 3.4 4x4 that I have pretty much given to my son. (Basically I gave him his own key and now he wont drive his car anymore)

I had some 33x12.5 R15 AT on it, but when I started taking it hunting I gave it more aggressive shoes. (I did not change the size of the tires)
Since the change, even though it defiantly works better in the woods the top end MPH on the highway sux! Its everything I can do to stay above 55 at the top of any decent incline... AND I live in Florida. Driving to and from GA hasn't been too much to ask of it, but my 18y.o son wants to take it to Tennessee with him this summer.

I've had it looked at and they said that the tires (weight and dia.) are the only reason they can come up with such a loss and that there's nothing wrong with the engine. Plus my son loves "the look" of these compared to the all terrain tires. At this point we are even kicking around the idea of having a Toyota V8 put in if we can find one, but I wasn't sure if anyone else has had this problem and maybe our mechanics have overlooked something.

If the V8 is our best alternative, can anyone point me to a thread that someone has done this. I've tried searching and when I look for v8 swap, no horse power or under powered in the search, I keep coming up with the 2016 Tacoma... I did see in another forum where someone put a Chevy 350 in one, but that's not what I want to do here.

 

joking ...but prob some different gears would be in order...

From a different forum..
https://www.yotatech.com/f116/33-inch-tires-what-gears-141709/

 

also is it auto or manual?

 

The increase in diameter will affect your rear end final gear ratio. I'm not sure if you changed load range when you went to a different tire, but if you went from load range c to e, there's a large weight difference.

I still can't see how a v6 would have a hard time pushing 33s. Had a buddy with a v6 auto on 35s and he still towed trailers around. He never re-geared the diffs.

Edit-maybe your truck is one of the few that came with like 3.58 gears.

 

my 2000 turns 17" rimmed tires decent...

 

Has it had a good tune up recently?

 

Thanks for the quick responses... It's a 5 speed manual, and they didn't do anything load range or gear related but I will look into it. I had a tune up around the same time I got new tires. Originally I thought something got screwed up and had them check and re-check. But three different mechanics (same shop) looked at it and came up with nothing. I have over 200k on the motor, but going from one extreme to another with three guys I've grown to trust made me want to believe it was the tires. I've talked to guys with 2nd Gen. 4 cylinders one said he had the same problems when the other just complained about the difference in MPG, but I don't know anyone with a 6cyl.

"Technically, 4.88s would be the correct size, but some people run 5.29s if they are running a heavy and wide tire. If you do a lot of interstate driving, I would probably run the 4.88s. If you mainly use it locally and offroading, 5.29s might be nice to have."
Technically I have no idea how to change any of this, but I printed it and will ask them if they do. If not I'll probably go to a shop that works on 4x4 trucks instead of a standard auto shop.

As far as towing, I haven't tried it, but with a full size 600# welding machine, a Co2 Cylinder, steel and 2 of my old tires in the bed it didn't seem to run any better or worse on flat roads and taking off.

Thanks again!! I'll let you know when I know something else.

 

Could the shop not test it by swapping tires/rims from another truck or even installing some used/new tires for a test drive to determine if that is forsure the case. Even if they charge for a mount and balance i would think its worth it before getting into gearing etc.

 

Dear Ray,

I am sorry to hear about your power problem on your 1998 Tacoma. From the sounds of your post, you have already found the culprit to your problem. Your 1998 Tacoma was running fine on its previous set of tires, and it became a freeway slug once you installed a more aggressive off road tire. I am sure there is nothing wrong with your 3.4 V6 motor. Please don't make more work for yourself than you have to.

I have the exact same rig except for mine is a year newer. My wife and I just have 31 inch BFG KO Tires on it. It does fine with these tires on it for our needs, but I am sure you probably wheel much harder than we do when you go hunting.

You will find the gear ratio to your rig on your Tacoma's door tag. It is in code form.

Take it easy,

Paul

 

Ray,

Can you post the axle code from your driver's door sticker? It should be like B03A or something of that sort.

Also, did the shops check your exhaust flow to ensure that your catalytic converter isn't somewhat plugged? Also, have you changed the fuel filter yet? If it's restricted you'll lose power.

 

Now I really don't see how a 3.4 5 speed would be sluggish on 33s. Post a pic of your door sticker, we'll see what gear ratio you have.

Also, I probably would go 4.88 with the 5speed and 33s. You'll be pretty high rpm on the highway. I'd do 4.56 at the highest

 

yeah its best to take it to a GOOD 4x4 shop or even a hot rod shop that has done ring and pinon changes. Also find a shop that guarantees their work.

 

Will it go over 55mph when you downshift to 4th?

 

Let me start by saying I wish I made this post back when I first started having issues. I really appreciate all of the input. I tried (and failed) the multi quote option so let me try to go one by one. Originally they told me to drive it for 50-100 miles or so to allow the computer to recalibrate or something like that. When I still wasn't impressed I asked if we could check everything out to see if something happened when they "tuned it up". When they came up short I asked if there may be a problem with my exhaust because it had happened with a different car of mine years before. Every time they said it was the tires. They had made the offer (when I still had the tires) to put the old ones back on, but they were so confident I was wasting everyone's time, I regrettably let it go.

As far was 55mph on the top of a hill, the only way I was getting there was in 4th. Staying in 5th gear I would slow to 40-45. Down shifting to third just sounded wrong even though I tried it a few times. It just sounded like it was working too hard and I didn't want to walk from North FL.

For me and what I needed it wasn't a big deal. I drove the truck to hunting camp where I left it all season. It was awesome in the woods; I went over and through everything I needed and a bunch of what I just wanted to! All these years I had the truck and I never used it for fun. What a waste!Anyway, come January I would drive it back home AT NIGHT where it would mostly sit hoping for a yard project or camping trip until next hunting season. Recently I gave up the 300 acre camp because I thought I was going to have to pay for college. So now it will probably spend the next 4 hunting seasons on a Daytona college campus or their hard packed beach since my son wants it instead of his 2001 lexus. He got a 4 year scholarship to Embry Riddle (realy proud of him!) and the only thing he wants is the truck, so it's hard to say no (especially once he had his own key).

Here is the sticker from the door:


I shared with one of my mechanic friends what I learned here in the earlier responses and he said to bring the truck in. He said he will go through it checking it out to make sure it's not only safe for a trip to Tennessee, but what was suggested here. He suggested this morning we get our hands on some smaller tires just to be sure if he doesn't find anything. That was before I read the post suggesting I do that. I told him this morning we shouldn't have to, but if he offers again tomorrow I will take him up on it. (He also wanted me to send him the door panel picture, I guess for the same reason)

I have a line on a possible v8 from a Lexus and maybe one from a Tundra as well. I still don't know which would be best but right now it honestly doesn't seem like either will set me back much more than a new set of 31's so I am still interested in it IF there is ANYTHING wrong with my motor. I didn't take the best care of it when it was my daily driver so I deserve what ever is coming my way... As far as a 4x4 or performance shop- I want to use what info I've learned here so far, and before I buy a v8 and all to go with it, I will bring it to a place called Nothside tires for their opinion. After I read your suggestion to use a pro shop tonight, I called a friend who spends his paychecks at one and he said they will put smaller tires on before they try to sell me anything. They did the same for him and his fake 4x4 F150.

Thanks again everyone. I do appreciate the feedback!

 

B06A = 8" 3.91 gears on a 2 pinion open diff. With 33" tires it will be a dog and will over work your motor. I just upgraded from my stock 4.10 gears on my 98 SR5 with a 3.4 & 5 speed, and it was a dog with 33.5" tires. I just upgraded to a set of 4.88 gears and it's restored my lost power from the taller tires, and put my gear ratio back to factory gearing and rpm range.

If you try to upgrade to a V8, you will have a lot more money into it vs doing a re-gear of your front and rear diffs. You will have the motor, trans adapter, radiator, wiring harness, exhaust, fuel system mods, motor mounts, etc, to find and get converted into your Tacoma. All of this will require more downtime during the conversion too.

I suggest you either get some 31 x 10.50 tires on it, or re-gear the diffs to 4.88's if you want to keep the 33" tires on it.

 

Thanks for the info and the life experience. The V8 is kinda the last resort, but this sounds like a great solution. I'm keeping my fingers crossed and I will let y'all know when I know more.
Thanks again.

 

4.56 will work, but you'll love the 4.88s. Especially in low gear.

 

I got curious to what was on mine...B03A=4.10? is that correct?

https://forum.ih8mud.com/threads/tacoma-gearing-question.199061/

 

Im turning 265/70/17 tires...seems ok. but I would like a little more top end but its not necessary for me at this point.