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Major BT7 Transmission Leak

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MadRiver

MadRiver

Jedi Knight
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Howdy gang!

My '59 BT7 has always had a slow transmission leak since I brought her home last year. However, it seems to have taken a turn for the worse. The weather was gorgeous in DC last weekend, so we decided to take the car for a few brief errands. Before we headed out, I topped up the transmission (which has overdrive) and off we went. Everything worked perfectly. Upon returning home, however, we noticed two lines of fluid stains on the pavement leading right into the garage. One was a steady line, demonstrating a dramatic leak, and parallel to it was a line left by something dripping. I checked the transmission fluid level, and she was just about empty. We covered probably no more than ten miles total.

I'm going to look at the angle drive, the rear seal and also see if everything is bolted up tightly (who knows what mischief the PO caused). But before I crawl under her, I wanted to ask if anyone had thoughts on the likely cause.

Thanks as always!

B.
 
Already sounds like you're going to be looking in the right places.

Not sure when a front xmsn seal was incorporated, but my BN6 box has a "reverse scroll" oil slinger on the input shaft, so depending on damage/wear, that could be another potential leak source.

Two (2) types of oil could be leaking from the bottom of the bellhousing; engine oil (which will be much darker, due to the presence of products of combustion) and transmission oil, which should still be as clear as when recently poured in.

Please do post back, as it will help future searches if the results to a fault are known.
 
Just a thought

If the oil is running out in a steady stream, why not jack the car up off the ground, empty the gear box and re fill the gear box with diesel( fuel oil or gas oil, what ever you call it over there), then look out for the leaks. The diesel will not harm the box or the overdrive unit. In fact when I pulled the transmission when changing the clutch I used diesel to wash it out and get all the bits of iron filings out, it is amazing what comes out of them and what congregates on the magnetic washers beneath that big brass cap.

Best of luck

Bob
 
Hi MadRiver, years ago, on my '63 BJ7,had a slow leak which got much worst over time, when I pulled the gearbox out I discovered one of the bolts that secured the bellhousing to trans case had worked its way completely out. Put bolt in with thread sealer, no problems. Just a thought! Genos2
 
Thanks guys! Hopefully I'll get some time this weekend to put her on jacks and see what I can see.
 
Wouldn't the big brass drain plug be something to look at for looseness? Also the top plug where the OD operating oil pressure valve is located. A lot of oil can come out there if it is loose. I have a lot of slow drip leaks from all the joints, but nothing that leaves a trail like that described.
 
Read my earlier post on finding transmission leaks with foot powder. Check the seal by the overdrive lever. I couldn't believe how much leaked from it. It dripped and blew back looking like it came from somewhere else.
 
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