Just passing on my experience trying to find a VSS for my T5.

I've spent hours trying to find a vehicle speed sensor (VSS) for my daily driver 1992 Firebird World Class T5 manual transmission. Vendor web sites say they have a compatible aftermarket VSS, but it is a 55mm for automatics rather than the 22mm straight shaft for the T5 (no wide flanges on the plastic barrel holding the metal shaft for the gear). Or they list the 22 mm VSS, but is unavailable when trying to order. The VSS GM Codes: D8G and D8M are discontinued. I'm guessing the aftermarket vendors did the same for compatible VSS parts.

I've called GM parts & transmission parts vendors as well as doing extensive web searches. It appears that aftermarket vendors have also discontinued the 22 mm VSS. I talked with a salesman from Whatever It Takes (WIT) transmission who owns a 2000 Camaro and knows that manual and auto trans take different VSS and he could not find one for me.

I'm not saying there aren't aftermarket VSS for my vehicle, but after extensive searching I've found some vendors on Ebay that have the aftermarket Standards Motor Parts SC40 VSS that is compatible with the following Camaro & Firebird models. I've ordered 1 each from 2 different vendors just to make sure I get at least one.

Standard part #SC40 is compatible with:

CHEVROLET
CAMARO
93 94 95
CHEVROLET
CAMARO IROC-Z
90
CHEVROLET
CAMARO RS
90 91 92
CHEVROLET
CAMARO Z28
91 92 93 94 95


PONTIAC
FIREBIRD
90 91 92 93 94 95
PONTIAC
FIREBIRD FORMULA
90 91 92 93 94 95
PONTIAC
FIREBIRD TRANS AM
90 91 92 93 94 95
PONTIAC
FIREBIRD TRANS AM GT
94
PONTIAC
FIREBIRD TRANS AM GTA
90 91 92


I'm hoping I don't get an e-mail from both Ebay vendors telling me they don't have the VSS I ordered. If that happens, at least I now know what vehicles in the bone yard may have one.

By the way, my old VSS rough idles 10 mph-stop at 500-800 rpm and throws out a heavy gas smell or jumps to 3,000 rpm. It's either sluggish low rpm or 3,000 and above; nothing in between. It's driveable, but miserable to drive.

 

I don't know a lot about all this yet but I've got a question. I am trying to finish up my 90 firebird. I took out the v-6, automatic and wire harness and replaced with 5.7, t-56 and wiring harness out of an 87 firebird. I'm having a tpi issue that I'm currently chasing but to you my question is, is this vss that your talking about what I would need to get my t-56 to talk reasonably with my speedo? I know that the 700r4 and the t-56 have differing pulses. One is low and the other high. (I don't remember right off which is which) I've purchased a signal converter from a company in Arkansas, don't remember their name either, that is supposed to get the two on the same level but isn't working so far. Would like to get speedo working cause I will get this thing to run if I have to put a carb on it.

 

You have to use the converter because, one is a sine wave the other is a square wave.

 

The T56 may need the same or different GM code VSS. If you know the year & model your T56 came from, you can look up the correct VSS. However, your T56 probably already has a VSS.

Also, on my transmission, there is a removable plastic gear, a separate part, that goes on the end of the VSS. The speedometer will not show the correct speed unless you have the correct VSS gear that matches your rear axle gearing. Probably not a big worry for you right now until you get your speedo working.

If you can't get your speedo working, you may want to start a new thread asking for help in getting your VSS, converter, and speedo working together.

Sounds like you are a pretty good wrench with all that you've accomplished. You must have had to do a bunch of fabrication to get there. I'm assuming you know that you have to beef up the suspension for that heavier V8.

Good luck with the speedometer.

 

Yes the suspension also came out of the 87. There's very little of the v-6 car left other than body and interior. Rear end and t-56 came out of a 94 formula. So I have the rear end and tranny out of one car and engine and wiring harness out of another. It's been an interesting project.

 

Yea!!! Ebay came through. I got the correct VSS for my T5 and just got through installing. Works great. However, I got the last one this vendor had. If anyone else is having trouble finding the correct VSS (Standard Motor Products SC40), here are some links to Ebay vendors who still have that specific VSS:
http://www.ebay.com/itm/Standard-Motor-Products-SC40-Speed-Sensor-/170816104678?pt=Motors_Car_Truck_Parts_Accessories&hash=item27c56ee8e6&vxp=mtrhttp://www.ebay.com/itm/Standard-Motor-Products-SC40-Vehicle-Speed-Sensor-/150803475061?pt=Motors_Car_Truck_Parts_Accessories&hash=item231c966a75&vxp=mtrhttp://www.ebay.com/itm/SMP-STANDARD-SC40-Transmission-Speed-Sensor-Vehicle-Speed-Sensor-/121086699332?pt=Motors_Car_Truck_Parts_Accessories&hash=item1c31546744&vxp=mtr

 

I got a 92 camaro that had 700r4 in it and I out a t5 in but the t5 had a cable driven speed sensor. It is the same size hole as the electronic speed sensor. I got a electronic speed sensor for a 92 camaro 5 speed and it fit right in there. Havent got trans in car yet but do you think this will work or no?

 

I don't know a lot about it but I'd say no it won't work and here's why. Your cable driven speedo has a worm gear on the shaft inside the trans but for the electric one you will have some kind of a rotor, kinda like in an electronic distributor. So that being said, I don't think it will work

 

3rd Gen VSS still use the gears like a cable speedo setup .

 

For every ones information, I contacted the distributor for the sc40 speed sensor. they are out of stock and no longer will produce them.

 

Maybe some help?

http://www.napaonline.com/Catalog/Ca...218_0354815394

 

thanks gary I do appreciate the assistance. I had checked with both NAPA stores locally who said they no longer carry this. I also had checked carpartsking.com who list the sc40, and they have not had one in stock for two years. gmparts direct also no longer have one in stock.

 

Hi,

For the ones who have arrived late, is there any solution for the VSS? Like purchasing another one and modding int? or using parts from an A/T VSS to rebuild this VSS?

Thanks

 

Speedometer gears plus a Speed Sensor, # 2PRS for MAF TPI or # 4PAC for MAP TPI from JagsThatRun.com. Double check with them on the application.

 

I am parting an 86 T/A and more than 1/2 the decision to buy was based on moving its T5 into our 92 Firebird. I recently learned that the 86 had a cable-driven VSS behind the dash in addition to being a different pulse than the 92. I presume the computer is the problem--taking the speedo from the 86 along with the VSS (if it works) would not solve the mismatch? The 92 is my 62k driver. I hate automatics, but the point in getting a whole car was to have everything factory-correct in the conversion.
Any advise? Does the pulse rate for the 92 give me options for sensors that are still available?

If it's going to be that much of a pita, maybe I'll keep the auto in the 92 and move the 5-speed setup into another car with a mechanical speedo where I can just avoid the issue. Then I don't have to worry about how long my driver is down for the switch either.

 

Details of your Car / Engine / Transmission / Axle/gears can be added to your

<------- profile by going here: http://www.thirdgen.org/forums/profi...do=editprofile

An 86 `Bird has a VSS in the transmission. (It's not the correct one for a 90-92.)
82-85 `Birds and 82-89 Camaros have cable driven speedometers with build-in optical VSS.

In fewer words, southbaysd asked the same question ("what to do for 90-92 T5 VSS?") and I answered it with one solution above. The aftermarket has you covered.

 

Sorry, obviously I had some of my details wrong. My previous research indicated 90-92 were all 4000 pulse, and 86 T/A was 2000 & might still have a cable speedo. (I've been stripping other parts of the 86 and have not crawled under to look at the connection.)
The jagsthatrun site says (#2 PRS) "The two-pulse (2000 pulses per mile) square wave (D.C. current or direct current) used on all TBI engines through 1992, all computer-controlled-carbureted engines, and on 1985–1989 TPI engines."
This should be correct for me, since our 92 is a 305 TBI.

That leaves one question: if an 86 T/A (305 carb) and our 92 305 TBI Firebird are both looking for a 2000 pulse signal, shouldn't the factory VSS work (possibly with gear changes)?

(I also updated my profile to show the '92 info.)

 

Having trouble following, but I can clear up some info:

All '90 - '92 f-body's have a 4K PPM magnetic VSS in the transmission.

For '90-'92 TBI: there is a 4-OUT BUFFER box under the dash to buffer the A/C signal (magnetic), and send 2K PPM and 4K PPM pulse streams out.

The speedometer gets a 4K PPM digital stream.

The ECM (TBI here) gets a 2K PPM digital stream.

The Cruise control gets a 2K PPM digital stream.

This is the same as the '86(?) through '89 Firebirds. Same VSS and same 4 OUT BUFFER box.

Not so with those year Camaros. They still used the cable driven speedometers with a 2K PPM optical pickup. The ECM and CC(?) received the 2K PPM digital streams (buffered).

RBob.

 

Thanks for the update!

I'm going to phrase differently than RBob but hopefully say something helpful.
The 86 TA 2000 VSS feeds the items in the car that require a signal.
The 92 TA 4000 VSS is a different signal type and uses a buffer box to split a 2000 signal to the ECM, 4000 to speedo, and

The suggested method (of using a 4000 aftermarket VSS fed by T5 speedo gears) lets the VSS feed the stock wiring in your 92 without changing the ECM, cruise, speedo, or buffer box. Going to a 2000 VSS could theoretically be done like a late 80s Bird but would require re-wiring things instead of leaving them like they are.

If the 86 VSS is functional, you could probably make a few bucks for it here on the classifieds.

 

Anybody have any ideas on where to find a SC40 VSS. Junkyards have not been much luck.

 

I have a '90-'92 factory VSS for a 5 spd. w/18 tooth gear

$80 shipped.

 

Sounds good. Send me your paypal info or email me at det006@gmail.com

 

SOLD

 

If anyone has a lead on one I'm still looking.

Thanks,

 

Question, is the VSS required for the ECM to operate the engine properly (tuning, etc.)? From what I can gather I think not. Seems the VSS is only used for the speedometer and cruise. So if I'm using the 3.1 V6 and T5 in a engine swap project, I should be able to use an aftermarket speed sensor and speedometer independent of the ECM. Am I missing anything?

 

Properly, yes absolutely.

Can you "get by" without it and "get by" with subtle nuances in drivability, fueling, and engine idle, absolutely.

 

Thank you, this confirms later information I found as well. Found this statement on a Fiero website:

"It must be emphasized that the VSS is used to control the idle speed when the vehicle is moving. Without the VSS, a vehicle may have stalling problems under certain conditions. Without a VSS, the engine computer (ECM) will not get the correct signals to run the engine for best fuel mileage. There are a lot of programs in the ECM that depend on the VSS. For best operation, the VSS needs to be connected and functioning."

 

I know this is an old thread but I have a T5 vss and a wc t5 if anyone needs either

 

Kenbob I'd like to buy the vss!!

 

Send a private message

 

Sent!

 

I know it's a long shot but do you still have that VSS you can email me at smokum92@hotmail.com