9C-1 Transmission Specs

[Lush696]

Greetings!

Can someone detail the specific upgrades of the HD 9C-1 transmission?
Does it have a shift kit?
Does it have extra clutch pack(s)?
What other heavy duty parts are in it?

Can any 700-R4 be upgraded to an HD?
What would have to be replaced to do this?

I'm trying to weigh the difference between having my current one rebuilt($2000) or getting a used 700 R-4 ($200) to keep her a-rolling!

Thanks, Mike

[silicon212]

The 9C1 transmission has the 3/4 throttle 4-3 downshift disabled in order to allow the car a higher top speed, but that's pretty much it.

[Lush696]

Hmmm -
I was expecting something like a shift kit, heavier bands & servo, etc???

[96capricemgr]

Judging by your other thread the car is a 94? This is critical infformation to answer any mechanical question.

Beyondthat first thing you need to do is got over this delusion that your 9C1 is some mysterious supercar. IT'S NOT. It is grandma's Caprice with a rubber floor, bad seats and inferior rear brakes, that is right, the discs since setup wrong by GM are a step backwards from drums under normal use.

Now that I crushed that dream, let me crush another, it is not a 700R4. It is 4L60E and you would need specifically a 94 other years will not readily interchange.

Few shops can truely build this tranny well, most local shops are willing to take your money but their work will not last as long as the original. Either use a 4L60E specialist and spend good money doing so ProBuilt, FLT, Rossler and a few others do really good 4L60E work that can handle easily 2 time stock power and more, or get a GM remanufactured tranny. There might be a good local shop but that is an expensive leap of faith, I tried it once and got burned badly, tranny ended up costing me over $100 a month since I paid like $1800 and it lasted 16 months. I then wised up and got a ProBuilt Automatics and it has been doing well for years behind a LOT more power.
Really though for most folks a GM remanufactured unit is a good idea, better built than most local shops and has a good warranty.

The servo is the "vette servo" used on all LT1 vehicles.

You may not like my reply but this belief that the 9C1 and SS are so special is just wrong and irritating, not to mention these incorrect beliefs blind a lot of people to useful information. Think of it this way, thay are all grandpa's Caprice, just one is in work clothes one is in an evening gown, that is pretty mkuch it. The iggest mechanical difference is the disc brakes in back but since GM used a drum proportioning valve they do not work in normal driving, just in panic stops, so they are a step backwards unless you modify the system to work right.

The external oil cooler blindly cools oil rather than regulating the temp with coolant tempature the way the tow package cars did. The power steering cooler is a joke at best, the "brake cooling" air dams cause wandring and excessive inner pad wear, the wider calipers compromise brake pad selection but the piston is the same size so no added brake performance in the front.

Maybe the only truely nice thing the 9C1 got over civilian cars is the trunk button outside the glove box, and ugly green hoses that theoretically will never wear out.

[94HeavyChevy]

96capricemgr, what size rear end and gears do you have in your caprice and how much power are you pushing from ur motor. im trying to change my rear from the stock 7.5inch and 2.73 gears to something that can hold alot more power and launch off the line alot better.

[Blue Bowtie]

A '94 should not have a 7.5" 10-bolt.

[96capricemgr]

My 96 civi L99 car came with a 7.5"

[silicon212]

Originally Posted by Lush696

Hmmm -
I was expecting something like a shift kit, heavier bands & servo, etc???

Mine has the standard servo, but the valve body calibration is a little harsher than with a normal 700R4/4L60. The 1-2 accumulator spring is a little heavier, resulting in a crisper 1-2 shift.

However, mine is a 1988.

If you have a '94, then it's a 4L60E which means a computer controls the shift points, the computer being the PCM.

Listen to '96 above - he knows what he's talking about with these cars.

A 9C1 is generally your basic taxicab set up to endure harsh driving better than the basic taxicab.

[Blue Bowtie]

Originally Posted by 96capricemgr

My 96 civi L99 car came with a 7.5"

Good call. I forget that some of the '94-96 9C1s also had the L99, depending upon what the department ordered. In those cases, there might be a 7.6" 10-bolt, even thought there never should have been one under a B-car.

[morrisrh]

I have both a 9C1 and non 9C1 Caprice and there are lots of mechanical differences, mainly to make more heavy duty, but not a supercar......

Beyond the trunk release button location and bigger brake rotors mentioned earlier, I like the second dome light, the auxiliary fuse box and terminals near the battery, heavy duty windshield wiper arms, quicker steering box and turn radius, bilstein shocks, HD springs, dash lights out switch, oil/tannie coolers with HD radiator, higher output alternator, lockout between a/c and power steering, and trannie calibration makes it easier for me to tow.....lots of this stuff can be bolted on a civie caprice, but too much work and cost, I was lucky to get an "Admin" 9C1 not a patrol car 9C1, so cloth seats front and rear, nice rug (no rubber), no spotlight or antenna holes.....only 100K miles on this 95 when I got so lots to go on this one, I put 300K on my old 89 9C1 before the body rusted off the frame.....

for tranny, I called the local state police barracks and asked to talk to mechanic, and asked him where they took their trannies for rebuild...he told me and I took there and they fixed and I put on 150K miles with no problem....I also bought one at a 9C1 boneyard for $300 (he said if it didn't work return it and he'd give me another one) and had a tranny shop install that and it was fine as well.....don't take to local tranny store chains, they can't fix right

[96capricemgr]

The brake rotors are not bigger.
The high amp alternator was standard on the LT1 was NOT a 9C1 specific thing.
The steering box ratio is a little quicker but not the turning radius seeing as most b-bodies rub the swaybar and frame in stock form, so how is it that the 9C1 could have a tighter steering radius?
The AC clutch thing is a programming thing and even the civilian cars are set to turn it off at less than 100% throttle. I have the software to read and look at the programming so don't bother arguing with me on this one either.

Exactly what about the Radiator is "heavy duty"? Is it the fact the 9C1 has the smallest cooling capacity? That would be because the driver's side tank is tiny to make room for the external oil cooler lines. Many of the civilian cars came with oil coolers in radiator(superior setup IMO), and I have only seen one civilian car that lacked the external tranny cooler they all had the in radiator one.

Shocks and springs are not worth discussing because at this age they are all shot.

Like so many before you you are putting the car up on a pedestal it does not deserve. Grasping at straws to pretend your car is somehow superior.

I have wrenched on a good handful of these cars, from daily drivers to heavily modified, have three in my drive way at this moment and put over 190K on 94-6 b-bodies. I know my stuff when it comes to these things.

I will say some of the MYTHS stem from facts of the 80s that no longer applied by 94.

[j cAT]

Originally Posted by morrisrh

I have both a 9C1 and non 9C1 Caprice

do you own a 96 impala ? or is this a caprice that you modified ?