[4+3 trans]...can it slip?
Thread Starter
Pro
Joined: Jan 2001
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From: Newton (Wichita Area) Kansas
[4+3 trans]...can it slip?
I'm not familiar with the mechanical workings of the 4+3's Overdrive section and I'm wondering if slippage is possible if it doesn't have enough fluid. TIA.
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
Yes.
Here is one of my 4+3 trannies sitting on the ramp in 2 pieces. On the left is the Borg Warner Super T-10 four speed. On the right is the overdrive unit which is an automatic 2 speed.
I just removed and replaced my tranny yesterday so that I could put that particular overdrive unit in because the other one failed. I had a leak somewhere and the ATF leaked out. The OD only holds about 1.7 quarts of fluid, and I lost 0.7 quarts. What was left overheated and burned up causing the clutch packs inside the OD to slip and PROBABLY cook themselves. I noticed this because when OD engaged the RPM instead of being at about 1800 at 70mph was at 3000 and when I took my foot off the gas it was like the car was in neutral. There was no engine braking.
So I just removed it and replaced it with this one so that I can take a look and rebuild it.
[Modified by scorp508, 1:38 PM 7/9/2002]
Here is one of my 4+3 trannies sitting on the ramp in 2 pieces. On the left is the Borg Warner Super T-10 four speed. On the right is the overdrive unit which is an automatic 2 speed.
I just removed and replaced my tranny yesterday so that I could put that particular overdrive unit in because the other one failed. I had a leak somewhere and the ATF leaked out. The OD only holds about 1.7 quarts of fluid, and I lost 0.7 quarts. What was left overheated and burned up causing the clutch packs inside the OD to slip and PROBABLY cook themselves. I noticed this because when OD engaged the RPM instead of being at about 1800 at 70mph was at 3000 and when I took my foot off the gas it was like the car was in neutral. There was no engine braking.
So I just removed it and replaced it with this one so that I can take a look and rebuild it.
[Modified by scorp508, 1:38 PM 7/9/2002]
Melting Slicks
Joined: Aug 2001
Posts: 2,516
Likes: 0
From: Lockport NY
Re: (scorp508)
I had a leak somewhere and the ATF leaked out...
...Well, how 'bout that!... :rolleyes:
( I know; it's a cheap shot, and a different trans, but I couldn't resist!) :D
[Modified by Rich B., 3:02 PM 7/9/2002]
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
Re: (Rich B.)
Do you recall a thread some months back where I said [4+3 trans] "And they all leak"?... And you said, "Mine doesn't!"...
...Well, how 'bout that!... :rolleyes:
( I know; it's a cheap shot, and a different trans, but I couldn't resist!) :D
...Well, how 'bout that!... :rolleyes:
( I know; it's a cheap shot, and a different trans, but I couldn't resist!) :D
Upon removal of mine you'll remember that I had to cut 1 cooling line, and the other twisted off of it's fitting at the lower radiator connection. So there are now two extra pressure fittings (1 on each line) that were not there before.
When I test drove it the first time the forward fitting at the radiator was leaking. I tightened it up and didn't SEE anymore leaking. That doesn't mean there couldn't of been a small leak unseen to the eye at speed while the lines were at pressure.
So, I'm still willing to say "mine doesn't" as I do not think it was the transmission itself. :D :boxing :cheers:
Melting Slicks
Joined: Aug 2001
Posts: 2,516
Likes: 0
From: Lockport NY
Re: (scorp508)
I'm still willing to say "mine doesn't" as I do not think it was the transmission itself. :D :boxing :cheers:
Someone else here pointed out something I've been doing wrong for years: not cleaning off the pan gasket surfaces before putting the new gasket on.
...I mean *dry* clean...I've always left them oily clean...(Like you would do with a new oil filter gasket)...
That leaves a thin film of oil on the mating surface...Kinda like the thin film between the crank and the crank bearing...And the effect is the same...
From now on, I clean squeaky-dry, then put my pan gaskets on!
You're (I'm!) never too old to learn... :yesnod:
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
Re: (Rich B.)
... :cuss ...
A big ole' :yesnod: to the dry clean of the tranny before putting a gasket or RTV on. I clean it all up and then rub it down with some brake cleaner.
Thread Starter
Pro
Joined: Jan 2001
Posts: 681
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From: Newton (Wichita Area) Kansas
Re: (scorp508)
Dang!!
My OD has had a small leak for quite some time. I don't think I've driven it more than 200 miles since April 1st but fluid has slowly been dripping out. Since the local drag strip doesn't offer test n' tune sessions during the week (argh!) I've been timing 0-60 mph runs on local roads. In April and May it was consisently running 4.0 sec times. In June it suddenly slowed down to 5.5 seconds. I think I let the leak go for too long! I hope I didn't fry anything in OD. I'll change the fluid tonight and see what happens.
My OD has had a small leak for quite some time. I don't think I've driven it more than 200 miles since April 1st but fluid has slowly been dripping out. Since the local drag strip doesn't offer test n' tune sessions during the week (argh!) I've been timing 0-60 mph runs on local roads. In April and May it was consisently running 4.0 sec times. In June it suddenly slowed down to 5.5 seconds. I think I let the leak go for too long! I hope I didn't fry anything in OD. I'll change the fluid tonight and see what happens.
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Thread Starter
Pro
Joined: Jan 2001
Posts: 681
Likes: 2
From: Newton (Wichita Area) Kansas
Re: (scorp508)
Well that makes a difference. No, I didn't have OD engaged in those runs. Pretty much drag racing.
It's been leaking around the pan gasket. I put it on last summer and I think the RTV cured too soon to flow into all the surface irregularities. RTV can be hard to work with when outside temps are 100 and the humidity is high. It totally sets up in 5 minutes sometimes.
My problem must be engine related. Either way I should probably fix this ATF leak ASAP.
It's been leaking around the pan gasket. I put it on last summer and I think the RTV cured too soon to flow into all the surface irregularities. RTV can be hard to work with when outside temps are 100 and the humidity is high. It totally sets up in 5 minutes sometimes.
My problem must be engine related. Either way I should probably fix this ATF leak ASAP.