how long should it take to replace the "drive gear" plastic gear 8 tooth w/ clip pin that holds it, which would require removing the the tail housing on a TH-350 street fighter transmission.

Im takling the car to a shop and want to know a ball park for labor time. It looks like something that can be don e without dropping the transmission. The 22 driven gear just goes in with teh cable its the 8 tooth drive gear that requires the tail housing to come off,

thanks for the help

 

I can't see more than a couple hours tops in a shop,get it on the lift drop the driveline pull the tail housing install the gears and put it back together.
This one is done on a bench but should give you an idea.

 

You think 2 hrs is a good ball park estimate? thanks

 

I think 2 hours should be ok as long as the exhaust does not have be removed. Sometimes removing the exhaust is quick and easy and sometimes it ends up being 90% of the work. The only way a shop will quote it is if it is in a Chiltons, Mitchell or GM time manual. Most aftermarket processes are not in the manual. As a rule if a bolt breaks coming a part it falls on the customer and if it breaks going together its on the tech. Techs job is to inspect bolts and clean threads.

If Bolts breaks on the exhaust it can be a nightmare. I remember a tech next to me working on an old GTX. He had to replace the Y pipe. It paid just under an hour. Bolt broke on the manifold, he could not get it out, he had to remove the manifold opps bolt broke holding the manifold to the head. He could not get that out either he had to pull the head. The bolt in the head was so bad it had to go to the machine shop. Ended up being a 3 day job. Half of that was trying to get bolts out. Most of the time a broken bolt can be removed in less than an hour.

 

Thank you; I got under the car and the "x cross pipping exhaust", & cross member is in the way & the drive shaft etc has to come off to get to the 4 bolts on the tail housing; It isn't anything you can just easily get to without taking other parts off 1st. 2 shops hrs max @ 130-1`50 per hr.

versus

taking the car to a local speedometer Speedo shop in phoenix. For $260 they put an adjustment "box" at the speedo housing with the car on a dyno machine which calibrates the speedometer making adjustments. Its a used transmission & im not trusting TCIs gear site that much. It could be right but if its wrong i just pissed away 300.00.

 

With exhaust rust is the biggest problem for unpredictable issues. You would be amazed how fast a real mechanic with the right tools and a lift can do an exhaust that is not rusted bad. Personally I have replaced Cat back exhausts in 20 minutes.

How far off is the speedo? I just upgraded my stock 14" wheels with big meaty 15" tires/rims. I know my Speedo is about 10% off. I use my phone for music and I just turn on Waze if I was doing any highway miles. I never even thought about changing the gears because this would have been the 3rd time I have changed something that would cause a gear change and who knows I May go back to the 14"s tires with summer. Even my daily GTO i rarely look at the Speedo. I have waze on for music and searching for cops all the time.

Based on the math one tooth difference is only about 4% error (21 vs 22 tooth). I think you would find that most 60s muscles cars out there are more then 4% off. I would not be surprised if new from the factory they where 2-3% off. Old school cop cars used to have to get their speedo calibrated every few months. This was mostly due to tire wear.

 

1967 camaro ; "TCI TH-350 transmission" is 5mph+ off when driving at 50 mph closer to 7+mph off at 60mph. need to replace with correct 8 tooth and 22 tooth drive gear (which i already bought from speedway)
Not sure if i should take it to a transmission shop or to the speed shop in Phoenix? The speed shop is saying instead of installing different gears they can add a speed reduction mechanical adapter for $260.00.

A transmission shop if i change the gear set and not go the adapter correction route is 2hrs at $250-300$ to replace the set of gears.
The question is which route would you go with?
A. Go the transmission shop route chasing gear ratios at 2hrs labor which is a risk supplying your own parts at 250$
Or,
B. Go The speedo shop route that adds the adjustment device to correct the mph? The adapter box screws on to the speedo housing than the cable screws into & the shop is claiming they use a dyno machine to calibrate ratios at $260.

 

OP

Do you know how many teeth and what size, small or large) your current Drive gear is?

There may be a driven gear that will work with what you have.

This calculator will show what driven gear is right per rear gear ratio and tire size.

Speedometer Driven Gear Calculator (stl-vettes.com)

8 large is what I have in my TH350 but I was asked by the shop that rebuilt it what one I wanted

 

Yes i already have the correct gears at least what TCI told me to get a 8 tooth drive gear with a 22 tooth driven gear. My transmission is 12 yrs old and has leaks so im really leaning towards
just doing the speed adapter at this junction as the cost is the same and if i go changing the gears and the car is still off the shop still gets paid regardless what some guy told me over a phone from TCI to get. The speedo adapter takes 10 minutes and the speed-o-shop can get it right the 1st time. I can keep my plastic gear set for the next transmission and just know when i buy a new one to change the gear set when the tranny is off the car to begin with to match my cars ratio. Summit unlike your shop doesn't build to order they just drop ship from their vendors and it would have been on me me 12 yrs ago to get the right gears at the jump. Since you said your shop asked you what gears you wanted you would have had to have know the right gears as well as that is something you would think the dang shop would do for you as they are a repair shop unlike summit racing which just is a parts supplier?

 

IMO, I would go with the adapter. The hardest part of this install with be jacking the car up. It allows the car to easily returned to stock and there is little chances of surprises like a crack tail housing or exhaust issues.

Getting an extra hour added to you bill with a comment like needed to re-flare exhaust and replace the clamps would not be surprising.

Does the adapter come with adjustments instructions? Does it need gear also?