- Jun 30, 2004
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I bought this 16oz bottle of Blue Devil Transmission Sealer about six months ago -- hadn't broken the seal on it until three weeks ago.
Good mechanics will tell you -- some of them, anyway -- that they "don't recommend chemical additives" for leaks -- whether for the engine, the cooling system and radiator, or the transmission. I consider that advice as a recommendation not to totally dismiss. But I'd had luck with the Blue Devil Rear Main Sealer product for engine-oil leaks of that sort.
And by the way -- I would not panic over small leaks from an old vehicle. It goes with the territory. However, I've been watching my leaks more closely lately
After replacing the rear window and rebuilding my suspension (ball-joints and shocks) back in October 2018, I became anal-retentive -- Obsessive-compulsive about raising the maintenance-level of my old 95 Trooper. [If you read stuff on this forum, you've heard enough about my "old Trooper" -- but -- Hey! Gimme a break!
] Anyway, I bought drop pans after fretting about the leaks. Of FREAKIN' COURSE it has leaks -- the odometer shows 188,500 miles right now!
The automatic tranny at first was leaking enough to require a one-quart top-up over less than a year's time, to the 9-quart capacity spec. I scrubbed the concrete garage floor and got rid of the mess, but the dark stain is still there. I bought some Valvoline "Transmission Stop Leak" for the top-up. The Valvoline is considered by mechanics as "just a Dexron-III alternative" for older transmissions; some opinions suggest you can just keep adding it to the regular Dexron-III, although Valvoline discourages that sort of usage. My leak attenuated only slightly, and I since drained and replaced all the Dexron in the tranny. I finally consulted the shop manual, which noted that leaks at the main-seal can sometimes be solved or reduced by re-torqueing the transmission attachment (to engine) bolts to factory spec. We did that, and the leak was very much reduced.
Even so, I saw that noticeable ambient temperature changes with the weather would evidence a more obvious leak. Of course, the drop-pan makes a leak look bigger than it is. Wiping it clean with a paper towel will prove it.
At this point, I'd notice a puddle every couple weeks -- enough to soak half a paper shop-towel. Maybe after a few days, a visible drop of Dexron redness would appear on the pan. Other times -- more than that.
So I finally decided to try the Blue Devil -- carefully. Attention to the promotional reviews shows promise that BD is more effective than Lucas or Barr's tranny sealers. The customer reviews are good, but some indicate that the stuff can swell your seals to the point where they "explode" -- people reporting that their cars suddenly began leaking Dexron like a sieve. That's probably why I was never too eager to try it.
The product instructions recommend 1 oz of BD for every quart of tranny fluid. [A full bottle of BD contains 16 oz, and I can imagine careless people who can't read the small print dumping the whole enchilada into their tranny.] I decided to add only three ounces mixed with three ounces of regular Dexron-III, or 1/3 ounce per quart. Thus, the tranny was topped up with another 1/5 of a quart.
I can say honestly that my Dexron leak has stopped. The drop pan is bone dry, and has remained so for three weeks. Even so, with some of the customer-review experiences in mind, I have slight misgivings.
The first think I noticed when preparing my six-ounces with BD -- it isn't miscible with Dexron. That is, you can shake it up; it doesn't really emulsify; and it eventually separates like oil and water with the BD on the bottom. One customer -- supposedly a mechanic -- noted that he pulled his tranny oil pan and found "black paint" covering the bottom. I can only guess that his seals were so dried out and shot that small particles of rubber provided the black sediment he calls "paint". Certainly, they don't paint the innards when they make transmissions!
This tranny has 60,000 miles on it. And I'm wondering to myself whether I should have it "flushed" again [last done 30,000 miles ago] or simply drained and refilled. Something to consider for next year, I suppose . . .
In the meantime, I had previously noticed that sometimes -- even filled to the Dexron capacity -- the transmission would seem to stick slightly in gear changes between 3rd and 4th on modest inclines. A web-site selling rebuilt transmissions notes that the 4L30-E GM transmission had design flaws that exhibit this symptom. Every so often -- the feel and sound of a "clunk" when it slips into the higher gear. After the BD had been in the tranny for about 10 days, I was driving up a hill where this behavior had shown before. This time, I noticed that it doesn't "clunk", but I could hear it "click". And since then, the clicking between gears seems to have disappeared. It all works -- just fine, simply capital, superb -- perfect -- absotively posilutely. Can't be sure what this means, exactly . . .
Good mechanics will tell you -- some of them, anyway -- that they "don't recommend chemical additives" for leaks -- whether for the engine, the cooling system and radiator, or the transmission. I consider that advice as a recommendation not to totally dismiss. But I'd had luck with the Blue Devil Rear Main Sealer product for engine-oil leaks of that sort.
And by the way -- I would not panic over small leaks from an old vehicle. It goes with the territory. However, I've been watching my leaks more closely lately
After replacing the rear window and rebuilding my suspension (ball-joints and shocks) back in October 2018, I became anal-retentive -- Obsessive-compulsive about raising the maintenance-level of my old 95 Trooper. [If you read stuff on this forum, you've heard enough about my "old Trooper" -- but -- Hey! Gimme a break!
] Anyway, I bought drop pans after fretting about the leaks. Of FREAKIN' COURSE it has leaks -- the odometer shows 188,500 miles right now!The automatic tranny at first was leaking enough to require a one-quart top-up over less than a year's time, to the 9-quart capacity spec. I scrubbed the concrete garage floor and got rid of the mess, but the dark stain is still there. I bought some Valvoline "Transmission Stop Leak" for the top-up. The Valvoline is considered by mechanics as "just a Dexron-III alternative" for older transmissions; some opinions suggest you can just keep adding it to the regular Dexron-III, although Valvoline discourages that sort of usage. My leak attenuated only slightly, and I since drained and replaced all the Dexron in the tranny. I finally consulted the shop manual, which noted that leaks at the main-seal can sometimes be solved or reduced by re-torqueing the transmission attachment (to engine) bolts to factory spec. We did that, and the leak was very much reduced.
Even so, I saw that noticeable ambient temperature changes with the weather would evidence a more obvious leak. Of course, the drop-pan makes a leak look bigger than it is. Wiping it clean with a paper towel will prove it.
At this point, I'd notice a puddle every couple weeks -- enough to soak half a paper shop-towel. Maybe after a few days, a visible drop of Dexron redness would appear on the pan. Other times -- more than that.
So I finally decided to try the Blue Devil -- carefully. Attention to the promotional reviews shows promise that BD is more effective than Lucas or Barr's tranny sealers. The customer reviews are good, but some indicate that the stuff can swell your seals to the point where they "explode" -- people reporting that their cars suddenly began leaking Dexron like a sieve. That's probably why I was never too eager to try it.
The product instructions recommend 1 oz of BD for every quart of tranny fluid. [A full bottle of BD contains 16 oz, and I can imagine careless people who can't read the small print dumping the whole enchilada into their tranny.] I decided to add only three ounces mixed with three ounces of regular Dexron-III, or 1/3 ounce per quart. Thus, the tranny was topped up with another 1/5 of a quart.
I can say honestly that my Dexron leak has stopped. The drop pan is bone dry, and has remained so for three weeks. Even so, with some of the customer-review experiences in mind, I have slight misgivings.
The first think I noticed when preparing my six-ounces with BD -- it isn't miscible with Dexron. That is, you can shake it up; it doesn't really emulsify; and it eventually separates like oil and water with the BD on the bottom. One customer -- supposedly a mechanic -- noted that he pulled his tranny oil pan and found "black paint" covering the bottom. I can only guess that his seals were so dried out and shot that small particles of rubber provided the black sediment he calls "paint". Certainly, they don't paint the innards when they make transmissions!
This tranny has 60,000 miles on it. And I'm wondering to myself whether I should have it "flushed" again [last done 30,000 miles ago] or simply drained and refilled. Something to consider for next year, I suppose . . .
In the meantime, I had previously noticed that sometimes -- even filled to the Dexron capacity -- the transmission would seem to stick slightly in gear changes between 3rd and 4th on modest inclines. A web-site selling rebuilt transmissions notes that the 4L30-E GM transmission had design flaws that exhibit this symptom. Every so often -- the feel and sound of a "clunk" when it slips into the higher gear. After the BD had been in the tranny for about 10 days, I was driving up a hill where this behavior had shown before. This time, I noticed that it doesn't "clunk", but I could hear it "click". And since then, the clicking between gears seems to have disappeared. It all works -- just fine, simply capital, superb -- perfect -- absotively posilutely. Can't be sure what this means, exactly . . .
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