Adding/Fixing Tachometer

First of I'm posting this for an older friend who just isn't as capable of using the internet so sorry if I don't have all the needed information.

He's got a 96' Tacoma with the V6 in it, his Tach is from I4, so the RPM reads off. He's trying to figure out if there's a way to change the signal coming into his current tach to show correctly or he's open to adding one a separate (wherever he feels best).

I have seen some forums on here saying to get a digital readout that uses the OBD2 data (Scangauge or UltraGauge) but I'm not sure if he'll go for that.

Any info or direction would be greatly appreciated, thanks guys.


Sidenotes:
-I think he's had a hard time finding a tach for a V6 so he's set on keeping the I4 one
-If using a gauge off the ODB2 data is by far the easiest feel free to let me know
-I know this is a long stretch but he really wants to be able to buy one from an actually store and were in a more rural part of OK so there's only really the big Autoparts stores, no specific performance places around here. With that said it may not be an option to go that route so please post any info even if it's not that route.

 

It could be done but much easier just to buy a new tach.

Investing in a scan gauge or ultra gauge is very expensive unless they also want to read all the other real time data.

I have not looked in years but universal aftermarket tachs were quite common .

They had a switch one selected for either 4,6 or 8 cylinders would that be an option.

Search Universal Tachometer on your big box store web sites . A quick search showed many options.

Search Universal Tachometer 12VDC should get you started.

Any questions feel free to DM me.

 

There should be a trim pot behind the tach face that can be adjusted. It requires taking the gauge apart and using and external tach or timing light that has rpm readout to make the adjustment. I found a video that should help. https://m.youtube.com/watch?v=ZxaPjCZSA-c

 

Is a trim pot going to be enough? I can’t watch the video where I’m at, but I suspect that would be for fine adjustments, not compensating for a different number of pulses

 

I had a friend back when who claimed it worked. He was a bullshitter so who knows. Worth a try I would guess. Seems to work in the video

 

Seems like a lot of work for what the OP was looking to do.

If that was all that needed done.

I have never heard of that fix .

 

A last resort for sure, plus now that I think about it the whole scale would still be inaccurate. A used cluster is the answer. Check Car-Part.com

 

You can rescale to the V6 by following (roughly) the same guide thats used for the MR2 tachs here.
https://frankensteinmotorworks.squarespace.com/shop/tachometer-fix-and-adjust-parts

as others have said, its going to be far simpler to just buy a V6 cluster for ~$130

 

Thanks for all the replies, I've talked to my friend with all your ideas and suggestions.
At the moment he is still prefers converting his original tach to work though he may opt for an aftermarket add on if the current plan falls through. He hasn't pulled apart the back of the tach yet, but he believes his doesn't have adjustment between the two even if that was an option. Just for reference an identical tach to his is below (I believe is early 95' truck, AUTO, 2WD).


Currently our plan is I've sent an email to TechnoVersions Home of Z-Car RT Diff Mount, MeterMatch, TachMatch and ShopRelief about their TachMatch, it's programable in the sense you can tell it what input in coming (V6 in our case) and what output you want (I4 in our case). We are hoping to get some further information from them just to 100% confirm it will work for the tach at my friend's request.
I'll update about any response I receive from them.

Any suggestions are still greatly appreciation and thanks again to those who replied already.

 

I was in the same situation as your friend. Bought a cluster off of the bay that was for a 4 cyl. Mine is a 6. Did a little research and came up with a tach adapter. Got that off eBay as well. Followed the instructions and with a little trial and error, presto! Correct rpm’s! https://www.ebay.com/itm/141931549970

 

My uncle might deal with the tachometer replace on his incoming Tacoma project. It's neat overall with new tires and ion wheels. We'll deal with the brake and tachometer issues first.