7 1/4 Sure grip really?

[slant6billy]

So some guy was looking for a rare 7 1/4 sure grip ( Mopar actually made 'em) on Facebook "what you got to sale". Supposed to be stronger than an open unit. I guess he was going for authentic? I've snapped a total of 1 7 1/4, and tore up 2 others that hummed and warmed like they would grenade any moment. These were not sure grips. I would never trust myself with a 7 1/4. I was trashing them with redneck modded slant. There are slants out there pushing far more power. I would not go less than an 8 1/4 for any slant, but I use a 20 pound sledge hammer to crack open my morning eggs.

 

[Jack Meoff]

Seems a mixed camp on the 7 1/4"
I've been beating the crap out of the one in my Caravelle for years and so far so good. The one in the Volare seems solid as a rock and I daily drive and beat the piss out of the one in my Fifth.....I've put something like 35-000 city/highway miles on that one alone without a complaint.

Even 904's.....
I can blow up a Chevy tranny going to the booze store but I've yet to pop either of my 904's or the 999 in my Fifth. I know people who won't even look at either rear or tranny but I've had no issue with either.

 

[alf44]

captain, why you say your 5th has a 999 trans? thought that was just a 904, unless yours is a overdrive??or lock up torque converter?

 

[Jack Meoff]

captain, why you say your 5th has a 999 trans? thought that was just a 904, unless yours is a overdrive??or lock up torque converter?

It has a lockup...

 

[alf44]

ok, good info

 

[Jack Meoff]

ok, good info

:sunny:

 

[kkritsilas]

A998s and A999 have the lower first gear, and they have more friction plates, 4 for A998, and 5 for the A999. My 318 2BBL Mirada has an A998, and the 318 4BBL Mirada and Cordoba both have A999s. The A998/A999 should be able to handle more torque than the A904, and the first gear in the A998/A999 is 2.74 vs. the 2.45 in the A904. I'm fairly sure that the A998/A999 used lockup torque convertors.

 

[Jack Meoff]

A998s and A999 have the lower first gear, and they have more friction plates, 4 for A998, and 5 for the A999. My 318 2BBL Mirada has an A998, and the 318 4BBL Nurada and Cordoba both have A999s. The A998/A999 should be able to handle more torque than the A904, and the first gear in the A998/A999 is 2.74 vs. the 2.45 in the A904. I'm fairly sure that the A998/A999 used lockup torque convertors.

Thank you for the clarification.
I never knew the first hear ratios.....
And yes my Fifth has a lockup.....drops in like clockwork at about 45 ish mph.
62 kms...

 

[kkritsilas]

The first gear ratio is why some report that going to an A727 seems to make lthe low end response worse; you lose some overall gear in comparison to the A998/A999. I personally think the best way to address that is not to go to an A727, but an A518, which is the overdrive version of the A727. With the .69 overdrive gear, you can then drop the rear axle ratio (say from 2.94:1 to 3.55:!) to get the low end performance back, while still getting reasonable mileage and reduced rpm on the highway.

Kostas

P.S. There is an overdrive version of the A998/A999 called the A500. But if you are thinking of moving to an A727, it is probably due to wanting a stronger transmission, and that would be the A518, which is based on the A727. The A904 was also called the 30RH, the A998 was also called the 31RH, and the A999 was called the 32RH, the A727 was called the 36RH. The A500 was called the 42RH, and the A518 was called the 46RH. In all of these aleternative names, the first digit is the number of forward gears, the second number was a rough approximation of the torque capacity, and the last letter (H in these examples) means that is was a hydraulically operated governor. Some of the transmissions exist as RE versions, which means electronically (=computer) controlled governonrs.

 

[alf44]

i have a 86 5th with 318 and sure its a 904. no overdrive. seems no lock up converter either as it shifted like a regular 904.

 

[Jack Meoff]

Maybe 87 was when they switched??
For sure mine has lookup.

 

[kkritsilas]

In all cases. check the fender tag codes. That is were I got the transmission types on my car. I would think that your 5th would have either an A998 or A999, from what I know, both are lockup. The A904 has the higher low gear ratio (2.45:1), so the car would be pretty sluggish off the line in comparison to an A998/A999 (2.79:1 low gear) transmission equipped car. The A904 wasn't really used much after 1981, and most V8 cars from that point on had A998/A999 transmissions. The A904 was still in production though, so anything is possible, although factory use in a 5th would be surprising.

It is also possible that your torque converter's lock up mechanism may not be working.

Overdrives first showed up in 89 (A500) and 91 (A518) or so, speaking strictly from memory (as per Allpar). The 5th does not have an A500 because the A500 came out after the 5th was out of production. In any case, the 4 speed overdrive rear wheel drive transmissions were really brought out with the pickups, never any of the rear wheel drive cars prior to Chrysler going all FWD for the cars. Donor vehicles for the A500 or A518s are the pickups, only.

Kostas

P.S. For what it is worth, the A904 got a lock up torque converter in 1978. Also, there is an A727 for the Slant 6, used in pickups.

 

[slant6billy]

Early 90s transmissions out of pickups and vans are the way to go. Some are non lock up and some are the A999- like the one in my 95 3/4 ton van. I will state this, my A999 has the best 1st gear out of any of my cars. My RE46 (518 electronic) does not launch like the A999. I had seen an ad for a "built" trans with a van first gear and some chatter about building the trans up using the lower first gear.

 

[brotherGood]

In my readings cap, all transmissions (904 variant, maybe 727 as well) went to lockup in the late 70s and early 80s. Being a civvy, you'd most likely have the plain jane 904. From how I understood it, the 998/999 was a 904 based trans, with different gearing and clutches I think. Otherwise referred to as "cop trans"

 

[Jack Meoff]

In my readings cap, all transmissions (904 variant, maybe 727 as well) went to lockup in the late 70s and early 80s. Being a civvy, you'd most likely have the plain jane 904. From how I understood it, the 998/999 was a 904 based trans, with different gearing and clutches I think. Otherwise referred to as "cop trans"

I'd have to do some re digging to make sure.
I think it was on Allpar I read that the Fifths got 999's
But like I said I'll have to reconfirm that.

 

[Jack Meoff]

In my readings cap, all transmissions (904 variant, maybe 727 as well) went to lockup in the late 70s and early 80s. Being a civvy, you'd most likely have the plain jane 904. From how I understood it, the 998/999 was a 904 based trans, with different gearing and clutches I think. Otherwise referred to as "cop trans"

I just cracked my FSM and they do indeed refer to my tranny as a 904LA.
Hmmmmmmmm...........
Curious.....neither my Caravelle or Volare have a lockup.

 

[brotherGood]

For some reason, I wanna say everything was lockup by 81. I think they did it to help with emissions and mileage..if I heard right. I've never really understood the purpose of lockup..but when I get to address the trans, I'll learn then..lol

 

[Mr C]

Funny, I've had no less than 5 M bodies (5ths and a Dippy) from 83 to 89 and all were 318 2bbl lock up trans, non Sure Grip cars.

Every single one had the lock up come on @ 50 mph/ 80 km/h.

Never had an issue with the differential in any of them.

 

[Jack Meoff]

Funny, I've had no less than 5 M bodies (5ths and a Dippy) from 83 to 89 and all were 318 2bbl lock up trans, non Sure Grip cars.

Every single one had the lock up come on @ 50 mph/ 80 km/h.

Never had an issue with the differential in any of them.

Mine kicks in right around 65 kms/hr. everytime.

My tranny fender tag code is DGA.

 

[AMP762]

My 81/6 LeBaron has a non lock-up,my 88 5th has lock-up,and my 79 Aspen 318 had lock-up.Maybe its a v8 thing,