Tranny chatter?

[b3uhbp]

Hello folks. I have a chatter in 4th and 5th gear at high speed coming from the tranny cover. The transmission only has 35k since overhaul so it's hard to think it's the transmission. What else could it be? U-joint? I have 75-90 GL4 gear lube in it now. Thanks for the help

 

[Torxhead]

U-joints would be a good place to start. Describe this chatter, is it a shifter shake? As I had a similar issue with the dreaded T5 once.

 

[Lumpy Grits]

CK ALL of your u-joints for play/slop and lube the slip splines on the driveshafts.
Re-ck the oil level in the tranny.
Ck your engine and tranny mounts.
LG

 

[b3uhbp]

U-joints would be a good place to start. Describe this chatter, is it a shifter shake? As I had a similar issue with the dreaded T5 once.

The chatter is hard to describe and it's not always present. No shifter shake. Sometimes when I put my hand on the shifter the sound is amplified but nearly any manuel transmission will do that. When the sound is present it's like something is under stress or tension. It shifts very smooth and I like the T5 for my use which is mostly pavement. Combined with 4.10 gears and 32/1150s it's a good setup. I have read that for mild use the T5 should last. I certainly hope so.

 

[b3uhbp]

CK ALL of your u-joints for play/slop and lube the slip splines on the driveshafts.
Re-ck the oil level in the tranny.
Ck your engine and tranny mounts.
LG

Good advice. I know the mounts are all good. I will check all the other components today and let you know what I fine. I don't think it is anything serious but I'm OCD when it comes to my jeep. Thanks

 

[Lumpy Grits]

Is this a T-5?
DON'T use 80W-90 in a T-5!
Use this--
Synchromesh manual transmission fluid ? Pennzoil®

The chatter very well could be from using the incorrect gear oil.
LG

 

[Torxhead]

Is this a T-5?
DON'T use 80W-90 in a T-5!
Use this--
Synchromesh manual transmission fluid ? Pennzoil®

The chatter very well could be from using the incorrect gear oil.
LG

That oil is a new one on me. My experience with pennzoil ended when I removed my valve cover and saw deposits from what I hear comes from a high parraffin content in their oil. I am thinking my T5 went south from the old style Detroit Locker that had high clearances at the diff gears.

 

[Torxhead]

Good advice. I know the mounts are all good. I will check all the other components today and let you know what I fine. I don't think it is anything serious but I'm OCD when it comes to my jeep. Thanks

Bad CJ motor mounts are hard to spot visually. I look for the engine valve cover getting to close to the firewall and the clutch bellcrank not being perpendicular to the frame. This means the engine is sagging to the rear. Bad CJ motor mounts can torque over an pull the clutch bellcrank off one of the pivots. More likely to happen on the trail when low range is being used.

 

[Lumpy Grits]

That oil is a new one on me. My experience with pennzoil ended when I removed my valve cover and saw deposits from what I hear comes from a high parraffin content in their oil. I am thinking my T5 went south from the old style Detroit Locker that had high clearances at the diff gears.

DL is not what kills the T5. It's the torque load from the OEM R&P's that doez.
LG

 

[b3uhbp]

Is this a T-5?
DON'T use 80W-90 in a T-5!
Use this--
Synchromesh manual transmission fluid ? Pennzoil®

The chatter very well could be from using the incorrect gear oil.
LG

Now I'm concerned. I researched the lube I'm using pretty extensively and chose Amzoil. What more can you tell about the difference between the 75-90 and Penzoil. Also, I assume 75-90 is good for my Dana 300' Dana 30 & AMC20? Thanks

 

[b3uhbp]

Bad CJ motor mounts are hard to spot visually. I look for the engine valve cover getting to close to the firewall and the clutch bellcrank not being perpendicular to the frame. This means the engine is sagging to the rear. Bad CJ motor mounts can torque over an pull the clutch bellcrank off one of the pivots. More likely to happen on the trail when low range is being used.

Engine was rebuilt and only has 35k miles. Mounts were all changed at that time and a local jeep shop told me they were all good. Seems to be good clearance between valve cover and firewall (good tip). Thanks

 

[Bent]

I found out the hard way that a little bit of bellhousing miss-alignment will cause a strange chatter. Now that you have some miles on it maybe put a jack under the oil pan and break torque on the bellhousing to engine block bolts and the trany to bellhousing bolts. Kick the transfer case around a little, and retorque.

 

[b3uhbp]

Is this a T-5?
DON'T use 80W-90 in a T-5!
Use this--
Synchromesh manual transmission fluid ? Pennzoil®

The chatter very well could be from using the incorrect gear oil.
LG

Couple of things. I spoke to a trusted mechanic and transmission guy and he reinforced your advice that 75-90 was not recommended for a T5 NWC and advised synchromesh. I also crossed checked the AMC part number from my owner's manual for the recommended lube and it seems to be synchromesh, so, I put penzoil synchromesh in the tranny. So far so good. I'm not sure yet if it will cure the chatter (have not driven enough) but I do think it shifts better, particularly down shifting. Thanks all.

 

[Tinman22]

Go too tremec's website

Go too FAQ's

T-5 lube ...world class t-5's synchromesh (prevents bushing and synchro de lamination)

T-5 lube.... Non world class t-5's dexIII (no laminated bushings or syncros)

Either will work one is less expensive.

 

[b3uhbp]

I'll check out Tremec. Thanks

 

[Lumpy Grits]

Go too tremec's website

Go too FAQ's

T-5 lube ...world class t-5's synchromesh (prevents bushing and synchro de lamination)

T-5 lube.... Non world class t-5's dexIII (no laminated bushings or syncros)

Either will work one is less expensive.

Dead wrong about Dex3 ATF use in the T-5.
AMC pay'd a heavy price for that stupid!
BW had told'em in advance it was the wrong lube, and they wouldn't back the claims that came in on the smoke'd T4 and T5 boxes.
LG

 

[Tinman22]

Amc..tremec...ford...gm...seems everyone Has a different idea.

Let's dig deeper.
Amc used ATF in 82 then syncro/bushing failure forced a move to straight GL-4 90wt ( AMC TSB 82V12 5000) in mid 82 by 83 it's all 90wt in 84 they moved too p-n 89-83-000-000 the 75/90wt so called fish oil since then it's become unavailable and Chrysler recommending a gl-3 oil.

Tremec at one time also recomended spirax dentax 50wt synthetic (low sulphur)but since then moved to ATF.

If you look further you will find the real problem is SULPHUR.
The t-5 trannys were being eaten alive by sulphur, you see sulphur eats bronze a key component in t-5 syncros and bushings. AMCs move to 90 wt was an attempt at a lube with less sulphur. Although better it still wasn't low enough hence 89-83-000-000 stinky oil very low sulphur. Now discontinued Chrysler says a GL-3 oil also low SULPHUR.

I'm only guessing here but since tremec has changed their tune from dentax 50 too ATF might they also have fixed their sulphur problem? I find it hard to believe that they,after all the t-5 lubrication issues would recommend a fluid on their own site that would ruin their tranny and leave them open too a ton of lawsuits . But then again maybe they too are stupid.

syncromesh will work $$$ Gear oil unless a GL-3 oil is wrong and my direction too the tremec site was also wrong.

In a past thread I said I used dentax 50 because it's what we use in our truck trannys and we've got a lot of it and we've had no problems I guess I know why now.

 

[Lumpy Grits]

Been run'n and rebuilding T-4/T-5's for 30 yrs now.
I use Valvoline 75W-90 syn in mine, and all the ones I have rebuilt with no issues.
Valvoline/Full synthetic gear oil SAE 75W-90 32 oz. VV975 at AutoZone.com
It wasn't the sulfur that killed the boxes.
The AMC, 'snake-oil' had the highest percentage of sulfur.
What the AMC stuff did was to make the seals hard as a rock and crack.

BTW-The GL4 oils of 30 years ago are NOT what you find today.
LG

 

[Lumpy Grits]

BTW: One other thing-The T4/T5 use a 2 piece shifter. They have a known history of coming apart.
Does the chatter nose reduce any when you hold the shifter?
LG

 

[b3uhbp]

BTW: One other thing-The T4/T5 use a 2 piece shifter. They have a known history of coming apart.
Does the chatter nose reduce any when you hold the shifter?
LG

Long time since I looked at this thread. Since I put pennzoil synchromesh in my T5 it shifts much better and is quieter. I did call Tremec and got a tech to cal me back. He recommended SAE 10w30 motor oil. Go figure. I imagine there is little difference between synchro and 30 weight.